i'm sorry to hear that man. something i do to memorialize people who were close to me is to do stuff that reminds me of them, and make sure their good aspects and characteristics live on. whatever you believe, that person hasn't left your life if their spirit and and personality live on through you and others
my more general suggestions are to take it easy on yourself, take it day by day, and try to talk about it with people if you want to-- humans benefit from "venting" a ton
time will take the sharp edge off, slowly but surely. if anyone reading this ever needs to talk to someone, you're always welcome to private message me on here. i used to work at a suicide hotline and 95% of calls are not suicide situations at all, they are "just" people that need to talk about something and you wouldn't believe how much people benefit from talking, even with a stranger
no man is an island OP. your close ones likely want to help but aren't sure how to approach you about it. you'll get through this and you'll be a more capable person coming out of it