We understand your eating disorder! I am the exact same way with social events, so I feel you
Do your friends know that you have an ED? If not, maybe consider telling them (but it's a pretty big deal, so make sure you absolutely want to first). If they already know about it, perhaps you could try explaining your fear of food to them?
Either way, you could also suggest some social activities that don't involve food and/or ones that involve exercise, like going swimming, walking to the park, hitting the gym together, rollerskating, etc.