Man hang in there stay strong. I kno how it feels to not even weigh your self anymore Cuz u kno deep down its just going to be a depressing number. But the good news is we can help. I would recommend kinda getting a solid diet in play first. With the strain your body is going thru I would highly recommend you look into juicing and the gerson theory. If you have Netflix there's a movie all about it. Seriously please look into it.
Stick with whole foods, fruits veggies, beans, chicken, fish. You should start to feel more energetic once ur diets in place.
From there I would say not to worry bout body building at first. Focus on simple things that will both add muscle and condition you. Lunges, step ups, pull ups, push ups, sit ups, planks.
After couple weeks start introducing some simple free weight movements and machines. After while of that I'd say go for your bulk program. But something like this is a good start. I can help you lay out something more specific if u want. Just pm me. Best wishes!