I know you don’t want to hear about the eating disorder, but we need to review the situation. The eating problem began as you developed a more intimate relationship. This means that they are connected.
Leaving after a week at the treatment center only gave you some of the tools, but not all of them. The social concerns you have are directly related to the eating problems. They are not two separate things.
I would recommend you take care of the eating concerns first. What you will learn is that your relationship to food is intimately connected to your relationship with others.
See if it is possible for you to get reevaluated by the program you were in. If not, you’ll want to talk to your general practitioner or psychiatrist. You will want to ask your family for help in setting up either of these appointments.
I know as a freshman in high school it may be hard for you to imagine that all these things are connected. I admire your courage for asking this question here, and hope that you will follow through on the suggestions.