Hi E. - The balance you are searching for can be found, but it takes work daily. Sometimes it's a mindset more than anything. They don't call it a balancing "act" for nothing... it takes practice and sometimes feels strange, like you are playing a part and you don't know the script! I work full-time as a teacher (I am blessed to have summers off), and the yearly routine of sending the kids off to day care with my husband by 6:45 a.m., working all day, rushing home, trying to spend quality time with them while cooking dinner and preparing lunches for the next day, baths, etc. can get VERY overwhelming very quickly. The only thing that has worked for us is to have a routine and stick to it. My husband and I also divide and conquer the chores. If yours is willing to help, that is GREAT - give him jobs to do. It may be that right now it is a lot for you since you just returned from maternity leave. I remember with my first it was crazy getting back to school because my mindset and focus had shifted so drastically now that I had a child. Give yourself a couple of months (at least!) to ease in and get the feeling of what it's like to be a working mom, and I know in time you'll feel less overwhelmed and have a daily schedule that works for all of you. It makes me personally sad that this life is the way it is, where both parents must work full-time just to support a basic lifestyle, unless one parents makes enough money of course.
As far as all the other stuff, it may be that extended family and friends who aren't super close to you have to take a backseat for a while. It's okay to say no to people while you get your bearings and establish your own family. If you do see friends for lunch or shopping, bring the baby once in a while. When you're cooking dinner, have the baby nearby in the exersaucer or swing (until your little one crawls away from you!) so s/he can see you and vice versa. Cram in as much time as possible but try to get out on your own or with friends at least once a month or so. I exercise daily and my husband knows it keeps me sane, so that is my alone time, at least a little each day is better than nothing.
For house cleaning, check out the other post from this weekend - there are great ideas there! Hang in there - the drowning feeling will come and go, it's an unfortunate part of being a working mom, but you will find the balance that works for you, don't worry. Good luck!!