Just kinda need some advice

Heyo quick introduction im 19yrs old and my name is kai just to some it up my Best friend died had a really bad breakup lost all my friends, i go to the gym i go on 2 hour walks i eat clean i play piano and guitar and read philosophy and fiction books, all this was to improve my mental state but its eating me alive at this rate i dont know, no matter how much self improvement i cant escape my mind, i just need some advice all of this happened in a span of a year