weight gain and stress with only bfn

as is I am now 314lbs the heaviest I have ever been. I hate myself for this. I am ttc, with a missing period for 104 days now, only negative tests and my doctor cant figure out what is going on with me. I have always fought with my weight and have now fallen to trying diet pills as nothing else has worked. I walk constantly even with collapsing arches in my feet and osteoarthritis in all my joints. moving is agony by I am trying. I make almost everything I eat from scratch and eat relatively healthy. I dont go out much. I dont eat much sugar, infact I try to avoid it. everytime I see myself in the mirror I get more and more depressed and not being able to even know why my body is working against me is making it worse. I have tried everything and it all feels hopeless.