Hello from the Pocono's.....Easier to just give up???

This is my 2nd round with weight loss attempts. The first time was 2 years ago which I was very successful at, but I worked out 3-5 hours a day 5,6 & sometimes 7 days a week for 5 months and went from a size 18 down to a 10. Then I faltered due to a bad scare with breast cancer where they had me pre-maturely diagnosed with stage 4 breast cancer (turned out months later to be something much, much less), then immediately after that I became pregnant (unplanned & previous pregnancies were life threatening.....I miscarried 2 months into it), finally my 16year old back injury (2 herniated lower lumbar discs) acted up and I've been in physical therapy since August. My doctor says I am now strong enough to work out at the gym, ect. During all of this I have been in the midst of a 3year long divorce coming out of a very abusive 20 year marriage (complete with restraining orders and all). My 21 year old son tried to kill himself just 3 months ago, my truck was repossesed and our home is in foreclosure and I am disabled due to severe panic attacks, anxiety disorder and depression. My stress level is completely off the charts. I am now back up to a size 16/18 and have gained back every inch I had lost. My goal is to lose it all again before Memorial Day (April would make me very happy!!) and to be able to maintain it this time around. I was, at my worst, 300lbs.....when working out I got down to 199 (didn't look it at all though). My largest size was a 4/5X and I went down to a 10. I was SOOOO much happier and had so much more energy when I lost it all. I want to feel that way again, but my body hurts....again. Every joint hurts, everything aches.....Sometimes I think it's just easier to give up and stay the way that I am. But I remember how good I felt and how everyone I met acted nicer to me when I looked better. I just need motivation to keep going.