Losing someone

Hello, i’m suffering from depression for a very long time now for more than 5 years and i cant do anything about it.

and now i have one more issue that even increases this depression more and more.

i’m gay and i have a straight best friend who i love more than much i’ll do anything for him, i want him to be mine but it’s impossible he doesn’t know about me and he cant know, but it kills me that we i cant be his boyfriend i cant confess my love to him, it kills me when he laughs with someone else, get help from someone else i want him and i don’t know what to do, every time i’m near him i’m more and more depressed, i don’t know if it’s better to get away from him or stay his best friend, he helped and still help me a lot through my depression but he doesn’t know that most of it because of him, he didn’t do anything wrong but my heart did, i really don’t know what to do it kills me i feel like i should be more away from him but i’m so afraid of losing him.