It is hard. Having to deal with it all alone sucks big time!
Perhaps try making one small change to your life - a reading group or a free class you can attend each week? Is there anyone who can babysit for you whilst you do this? Anything to make a small difference yet not be too much of an effort that you wont be able to maintain it.
If not, could you try doing something different with your kids that you dont do at present?
Giving yourself something to look forward to is the best thing you can do for yourself.
Fwiw - your post resonated strongly with me - it's how I've felt many many times.
