Help a Mercy Play Reaper?

So generally I play characters that work better at a range: Mercy, Hanzo, Junkrat, etc. I used to play Reaper WAY back before I discovered Mercy, but now that I'm trying to play him again, I've discovered I'm too timid? I try to go in and get close, but I generally get too 'omg so much is happening at once' and I don't kill anything. I could really use some good general suggestions for him as well as sort of how to get used to close combat again? And yes, I've looked at guide videos, but a lot of them are older and not quite as applicable anymore.