Hi Anna!
Restarting is tough, but it's something we have to do, right? You don't necessarily have to dive head first into it, though! What if you could change one thing today that would help you along? Just one thing? Like making sure to get all your water in, or your recommended amount of fruit & veg? Or even just a couple minutes of exercise like walking?
There are plenty of support groups around, ones based on age (30 or 40 somethings), there's a Dieting with Obstacles section that might help, and there's even a WW section, too! You don't have 100 lbs to lose, but there's the 100 lb club that is quite active & very supportive.
Even if you do happen to lose slowly, wouldn't weighing less on your 40th birthay than you do now be a fabulous thing?
Take some time to look around & post wherever you're comfortable.
Best of success!!