Theodora from what you have said on other threads, your husband died quite recently.
I think you have an urealistic expectation of how long the grieving period can be, especially after a long and happy marriage, and you are trying to second guess how long people expect your recovery will take. You are also assuming that they will expext a quick recovery. Actually I very much doubt if that is what they are thinking, what they want is for you to concentrate on yourself and how you feel, instead of worrying about others.
I suspect, also, that you have always been the kind of person who rallys round and helps other people, always a giver and that you are now finding it very difficult to be a taker.
So, I am with others, go back to therapy and instead of doing it thinking how soon you can stop doing it and cease being a burden, try and think about how long you will need it to come to terms with your grief.
You were obvious a good and loving mother, with a son that appreciates it, which means, knowing how much you have done for him in your life, he is glad to have a chance to show that by helping you when you are dragged down with grief.
The best thing you can do is accept everything he offers and use it to your best advantage, istead of thinking how soon can you discard it.
This the point when you need to take rather than give, accept that a loss like yours takes a long time to recover from, even partially and willingly accept all the help you are offered. Take little steps, and slowly and you will bit by bit recover. Expect to be back to normal next week and your unrealistic hopes will make life more difficult for everyone.