you know, the feeling after you fapped. You feel like you have been drunk and your head is messed up. You can't concentrate and bound to make a lot of mistakes. You get angry easily for small reason and etc. How do you survive these bad things post pmo?
There are lots of things you can do to make it better (eating well, exercise, fun activities etc) but at the end of the day there is likely to still be some discomfort that you'll just have to get through. When you think about it, there are many occasions when you have to do this and while its hard, its still manageable (being sick, injured, bad personal/family news, etc).
I usually see it as an additional exercise of willpower and discipline - trying to muscle through the day, remain confident and happy after an episode of failure and guilt (e.g. after relapsing). This shouldn't be an excuse to relapse, but it's just the mindset I use whenever I relapse and fail at things in general and it quickly gets me back on my feet.
You have to get back up and keep moving forward to your goals. I've been there far too many times. Take note of the thoughts and feelings and use them to help you prevent falling in the future.