What should I do with this delimma. I may have "killed" a friend by making him laugh too much in the hospital?

A friend of mine visited a mutual friend who was in the hospital recovering from a heart attack (he was only 42..I am 32) and when I asked how he was he said he could use a laugh, you should go cheer him up...I am kind of known for my jokes with my buds...so I went to see him and was hangin just seeing how he was and I could tell he was down in the dumps so i started telling a few jokes I had recently heard and he seemed really happy and was laughing, then he really cracked up when I told this stupid guy in a bar with a penguin joke and then he went into cardiac arrest and they never could revive him. His Mom is really pissed at me and I feel horrible myself...i wish i would have never gone to see him so he would still be alive. I really want to go to the funeral but I know I am not welcome by his mom...I have tried calling her several times to tell her how sorry i am but well she thinks i killed her son so she hates my guts is a nice way to put it. Should i skip any thought of the funeral? Any ideas on how I can make it up to his mom??