I have a personality that does not cave in to social pressures. That does not always serve me well, but in this context, it would.
I also don’t have any family nearby that we regularly associate with, so the issue never comes up.
Was it a situation where someone actually tried to convince or pressure you to eat the wrong things, or did you just do it to look “normal” to everyone and ate whatever was in front of you without trying to modify your choices?
You are going to have to commit to change if you are going to be successful at this, and that may include changes in how you respond in social situations, or how often you participate in them. If you keep eating the same things you have always eaten, but of course for “reasons beyond your control,” nothing is going to change.
Tip: these things are within your control. You just have to decide what you are going to do, and then actually do it.