On the topic of "support your friends", if there's a funeral for someone you weren't super close with but your friend knew well and you're not sure whether to go, I would recommend just going, sitting up the back, offering your condolences if the opportunity comes up, and leaving. I've failed to do this twice. Nobody else said or did anything, but I regretted it.
It's also ok not to attend funerals at all, even if you were close. I broke down every funeral I went to and would rather avoid that in the future.
Sometimes in life you just have to do stuff, even if you hate it.
These things also have a tendency to become easier the more you do it, so advising people to just not do it seems horrible advice.
Not showing up to a funeral of someone you were close to just because of your own discomfort is plain weird.