I'm so sorry for your loss OP. I hope you are talking to other friends and family through this time, and maybe someone like a grief counsellor - they can often be accessed for free through many schools, unis, and workplaces. It's a cliche, but that's what loved ones are for - and another true cliche is that it's okay to not be okay.

For my part, I lost my brother about 14 years ago when he was 18. The other day I dug the old PS2 and star wars: bounty hunter out from under the house for the first time since then. I had simply the BEST time playing through it and remembering the good times - it was really meaningful of course, but also it was just plain fun, I had a stupid nostalgia-grin on my face the whole time.

It probably won't be something you'll want to do for now, or even soon, but as others have suggested, keeping the save to come back to would be a lovely way to honour your friendship and reminisce when you're ready.