No to the penicillin. You don't want antibiotics when you don't absolutely need them, you are reporting enough problems without harming your immune system needlessly. As to the rest, your doctors are way better informed than anyone on this website. It could be so many things, thyroid, blood sugar, nutritional deficiencies, etc. Just a lot that can go wrong. If your docs can't find anything and you're not suffering from something like, say, severe anxiety, find better docs. Hope it all works out.