I suggest you send them what you have. It is much better than sending nothing. Forget for a moment about not good enough, because it can never be. Theses can take a lifetime to write, and it will never be perfect. I am sure that you have been working on it, so your supervisors might as well appreciate your work. Or show it to your friend. But i'd recommend it sending better to supervisors. I have sent to mine some really shitty version, but the got some comments and could see, where I need to work more, whether I was heading right direction.

Go for that drink with a friend! When you see yourself randomly surfing on the net, it is really time for a drink or fresh air, or smth else...

For sports, you do not have to set up some big goals. You don't even have to go to the gym :) Do some push-ups and observe how this increases your productivity :) on the very busy days with thesis I used to do some quick sports even in university toilet to get my brain working better. It really helps! I would have been much worse without sports. I never had good condition, but it was eventually getting better - see it more as something what helps you work on the thesis.

After all, you don't have to spend time of the thesis. You may decide that you want to, because you want the degree.

Ok, choose what fits you from what I wrote, but go out with friends - either you talk about thesis or smth else, changing the scenery a bit might help you get more perspective.