Hi Nicole,
It sounds like you have a couple of different issues you want to deal with. On the 4th of July party, if these people were your friends and you had fun with them, you should go and ENJOY yourself. The more you shut people out and the more reclusive you become, the harder it will be to start losing weight. We all would like to enter a cocoon and not come out until we've morphed into the beautiful butterfly, but that's not how life works. Just remember, maintaining the status quo with your diet and exercise, people's metabolism slow and every 3 to 5 years you will gain 5 pounds. That means, a lot of the people you are afraid will be judging you will have gained at least 10-15 pounds too. Some of them will have gained more, and some will have upped their exercise regime or adjusted their diets to match their new metabolism and will have stayed the same or lost weight. If they are your friends, they will just want your presence and will enjoy your company. That doesn't mean they won't notice you gained weight and some may even come right out and say something about it either to you or behind your back, but it doesn't reflect on what kind of person they think you are. NOW, if the party is among a group of people who all work in the exercise field, then they may be judging you based on your appearance, but then they would all just be a bunch of exercise anorexics and not quite right in the head anyway :D
As to the issue of weight loss and motivation, I have my own 25 pounds I'd like to lose and am my own worst enemy when it comes to doing it. I think, since you successfully lost weight in your 20s, you should try to make a list of what you did then and try to incorporate some of those things into your routine. I agree with the moms who said to talk to your husband about what you want to do, you need his emotional support and you need him to watch the kids while you take a half-hour to hour a day for yourself. You deserve it! If you have a friend you can work out with, that's even better. Also, do as much physical play as you can with your kids. Run around, play tag, play hopscotch, soccer, throw the little ones up in the air or just lift them above your head - you have your own set of weights that will love being played with! I have a daughter who just turned 6. She is becoming aware of the weight I gained, and so when I woke up this morning I was thinking about things I could do with her that would be good for both of us, and would burn some calories for me (granted I only have one child which is why you really need hubby's help, you don't want to use your kids as your excuse why you can't exercise). I want my daughter to improve her swimming, which is something she'd like as well. I plan on putting a life jacket and swim goggles on her and swimming laps around the lagoon near my parents house. In the moments when I woke up and dreamed this idea up, I was thinking we could do 10 push ups, 10 situps, and then swim, but in reality, I'll be doing well if we get the swimming in.
So my advice is, revisit what worked in the past, get a journal write down all your mesurements, upper arms, thighs, chest, waist, hips. Then right down every little bit of exercise you do each day. (Include things like lifted the youngest above my head 5 times - things that don't mentally feel like exercise, but are). Once a week, write down your new measurements and weight. The measurements are important because as you tone, you add muscle which weighs more than fat, if the workouts you do include weights you may gain a little while you are slimming down. BUT, muscle burns more calories than fat so you definitely want to lift what you can when you can.
Go to the party, reconnect with friends, maybe you'll find a new workout buddy (assuming the party is close to where you live). And like the Nike ads say, Just Do It!
Best wishes,
A.