I'm sure it will take you days to read through all the responses, so you've clearly hit a chord! Knowing that may not help you feel better long-term, though.
I want to add this note to my original post below: Parents of neuro-typical kids underestimate how hard it is to parent special needs kids. It makes the job of mothering 10x harder and can eliminate many recreational/working options available to other moms. It also puts stress on a marriage. You're also in greater danger of mother burn-out, which means finding something to alleviate the stress is that much more important. I hope you have support in terms of services and a community of people who can give you ideas and let you know you're not alone w/your kids' special issues.
I finished my PhD in 2006 and decided to stay home w/my kids. It was a big jump going from reading Kant to reading Katz. I have 2 children--my oldest, (5), is high-functioning autistic. My daughter (19 mos.) probably is as well. I felt it important to stay home so that I could keep my family functional. I was tired of trying to do 2 full-time jobs. I was unhappy trying to take care of extra stuff at home due to my son and also meet deadlines, etc., at school/work (I taught for years while a grad student). I knew that life had to be more than rushing from one thing to another, and I wanted to run my house according to my values.
It has been very hard being home. I'm a goal-oriented person, and it's hard to have those at home. We go through periods of tough times w/my son, though now we're in a great period. I am never able to do scholarly work b/c of the consistent time you need to do it. So being satisfied at home has been tough. It's involved me knowing myself, having a different perspective on life (so that I value the things I have, not the ones I don't), and being creative in finding time to do things that make me feel more satisfied.
If you feel being home is right for you and your family, then don't feel pressure to get a job as the answer. It might work for people w/"neuro-typical" kids. Some moms of special needs kids work to get away from the problems, and I can understand that impulse. It wouldn't work for us. And many stressors come with working as well. One person has suggested getting a part-time job at nights while your husband handles the kids, but how will it help to have less time w/him? I wouldn't jump too quickly to that answer.
My point is, if you want to be home (but have it be more fulfilling), then you should know that being home and being involved is important and rare. I am thankful for moms who work and make it work for their families--they are my son's therapists and teachers, our doctors, etc., and almost all of my friends work full or part time (and many of them have family close to help out, etc., which we don't). But if you want to stay home, then try to find a way to make staying home work for you and know that it's valuable. Read books that talk about how it's valuable, if it helps.
Though I know it's important to stay home, I--like you--suffer from feeling like life needs to be more. If you feel this is something that needs medicinal help--if it's gone on too long, affects your ability to take care of your kids, seems to be beyond your control, etc.--then talk to your doc about anti-depressants. Most people I know--working moms, non-moms, etc--are on anti-depressants! I've chosen to avoid them b/c of a bad experience I once had, but many people do very well on them.
I also find it important for me to think about what i WANT to do--in a perfect world, given infinite time and space, what would you want to do? Try to think about what would make you feel better. Are you a goal-oriented person? Or someone more creative? Etc.? Then work w/your husband on solutions. For example:
--do you feel the need to be accomplished at home? Then see home as your work space and take charge of it--make it the ideal you want it to be. (I make my own bread, have a garden, and am working to create a family food culture, etc.) See it as your space and be as active as possible in it.
--do you feel the need to have "work" that you can do at home? Talk to your husband about having 1 night a week to yourself or finding time during your kids' naps to take up a project. Many women work from home these days w/the help of online resources. They sell things on Ebay, become demonstrators for companies like "Stampin' Up!," etc. If you want to write, look into writing a book. It can be a small project but still make you feel accomplished. If you really think working outside the home would help, then find a job that you can do minimally to satsify that need but not disrupt your family life.
--Are you active? Do you want to exercise? Enroll (if possible) in a gym that has child care (many health care companies provide rebates for memberships). Enroll your kids in swim lessons and do laps while they have their lessons. Have a scheduled exercise time like walking/jogging that can include the kids.
--Are you creative? Find a way to do projects. Work w/your husband to get 1 night a week/weekend. Make a "project time" every day where your kids do structured projects while you do your own project (or let them have tv time--sometimes, you just have to survive). Have your own craft space to work in. Get involved w/a group of people who stamp, scrapbook, etc. (which will give you adult time as well).
--Do you need to be around people? Find a mom's day out group, be part of something at church or another organization where you can take your kids for their activity while you talk to moms. Or if you have the $, hire a babysitter to do the same.
--Do you just need time to sit and breathe? Take one night a week to watch a movie and sip tea in your bedroom, or hire a babysitter so you can go to a bookstore, drink coffee, and read a book 1/wk.
These are just some ideas. Others have posted ideas like going back to school (when your kids are older, maybe, unless you have the $ now, or trying to do it online). Many opportunities exist for moms these days b/c of the internet that didn't use to be possible, but you have to know yourself and what you want out of your life first.
Our options are very limited, so we have to be creative in how we make things work for our family. I don't want to change things at home--I just want to have more time for me. You can make it work.
You're not alone in feeling discouraged. We're people too, not just moms, and we have needs and interests. It'd be nice to think we could just make ourselves be happy w/never-ending tasks, but that's not very helpful or realistic. You don't have to ditch being at home to be happy, so think about how you can be home and be happy, OR think seriously about whether you need something outside the home too.
Best of luck, J.