diary
I have a lot of failure that really makes me feel felt disappointment and disgusting, but then after a few hours i always restart my mind because that i need to be positive and strong no matter what does the situation
No matter what the ... [time/situaution/place/person/option etc] is a very good phrase to use.
Disgusting is not the correct adjective here. That word is usually to do with morality or cleanliness.
Good English though!