Definitely go back to the GP. It sounds as if all your symptoms have returned at the mere THOUGHT of a return to work, so you are not well yet. And you may take several months to get well. I too have been there. It took six months to begin to recover, and then I was offered, and accepted, an SA. Even after that it took over a year before I could really call myself better, and the stress still pops up every so often to remind me what it felt like. So, you are (I hope) employed under a contract which offers you a good long time on sick pay, so you don't need to worry about finances. That means you are not under financial pressure to return just yet. You seem to have supportive people around you, so that's good too. Rest. Relax, Recover. It took months to get to this stage, it may take months to recover. So let it. The wider picture is that this too shall pass. I am sending positive and supportive thoughts your way!