Well, why continue the charade of family at your own expense? Is this a long trip? Can you call and ask your Mom if it's ok that you don't come right now, and go later (when the rest of the family isn't around?)

At my mom's 80th birthday/family reunion, a few relatives didn't show...and one group drove ten hours, ate dinner and drove back. So? You won't feel guilt over not seeing the others... and if you find another way to keep in touch with your mom, you won't have to even consider guilt when she passes.

I vote don't go. You aren't going to feel good about it either way imo, so why put your physical health at risk by going? Make the call asap and end this terror inside. Then get to work on how you can remedy wanting to see your mom but not feeling her jabs.