What a horrible accident. I'm so sorry for your loss.
I understand your apprehension on seeing your friends after gaining a lot of weight. I went through something similar, and gained a lot of weight about 15 years ago. I was terrified to see old friends I hadn't seen since college because I was the athlete of the group. I was the 16% body fat, runner of the group, and had gained so much weight as to be unrecognizable. It was scary, but I sucked it up and just went anyway. I said something to one of the women about gaining so much weight, and you know what she said? "You look the same to me." Now, there is no way I looked the same (I was about 8 sizes larger and my face was so round you couldn't tell if i even had cheek bones), but she looked through that and saw her friend from college. I was still the same happy, upbeat personality, and that's what she saw.
It's pretty normal to feel weird about your body -- in fact, I'd be surprised if anyone in your group of college friends doesn't feel weird about his or her body -- regardless of size, but feel the weird and do it anyway (to paraphrase something someone once told me about fear). I'm guessing you're not giving these people enough credit for being true friends.
Like my mom always says: Those who mind don't matter, and those who matter don't mind.
Sending you light and healing loving energy to get you through this time of grief.