Accepting dinner in your room is what is known as a "safety behavior". A safety behavior is done specifically to avoid anxiety or anxiety-producing situations, not because you actually want to do it.

By using safety behaviors to avoid anxiety and the situations that causes it or makes it worse, you are preventing yourself from facing and overcoming the anxiety.

Therefore, my advice is to prepare what is called an "anxiety ladder". First, list maybe ten activities that you would like to do but are not doing at all, or not doing enough, because of anxiety. Second, rank them from most difficult/anxiety provoking to least difficult/anxiety provoking. Third, start doing every day, as often as you can, the two or three items that are at the bottom of the list. Fourth, as those items start to feel relatively easy to do, and not so anxiety-provoking, move up the ladder and start taking on the next task on the ladder.