<human>: Quick background: Year and a half-ish ago at my heaviest I was 349, got serious about losing weight and got down to 298 by Jan. of this year. Then things tarted going badly. I had some health problems and got depressed about going blind, etc. you know, small stuff... diet and exercise tanked, and I got back to 320. 

At that point, I got fed up and got down to 300 again within about 3wks, then the eyesight took a major turn for the worse and BLAH! Again, feeling down, etc. Got back to 310. 

Tired now of being fat *and* unable to see, I decided that I can at least do something about the weight. I'm back to about 303 now, after a week or so and tonight I did the W1D1 of Couch to 5k... which totally kicked my as, but I did it and felt great afterward. - Yay me!

So, how do you keep motivated to lose weight and stay focused on that while dealing with depressing shit? I have surgery coming up in a few months that will either help my eyesight (I only have one eye) or make it worse and I've been stressed over that. Work is getting hard to see to do, and I have a family to provide for, etc. 

On the plus side, I'm going out of town for a month and taking time off work, so that should ease some job stress. The place I'll be staying at has a full gym and I plan to take advantage of it. I'll be away from friends and family and won't have a lot of distractions, so I intend to really focus on the diet and building up an exercise routine. 

I do good when I focus, but when I get depressed, I derail entirely. If anyone has any advice on combating with that, I'd love to hear it.

I know regular exercise helps with depression and losing weight gives me something to feel good about, but when I actually hit a low point, my brain doesn't make that connection and I just sort of go into lump-on-the-couch mode.

Summarize the given text in a few sentences.
<bot>: I'm fat and my only eyeball's falling to bits and it's making me sad and I keep screwing up my diet/exercise as a result - help.