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!