does stress hinder the healing process? does doing too much too soon hinder also?

Yes and yes. Pain can also slow healing. That's why your doctor prescribes medication and there are limits on lifting, etc., after surgery. Rest is the best thing for your body, as is relaxation. Think of your body in this case a little bit like a computer. If you ask it to do one thing at a time (heal), it does it very well and very efficiently, but every time you ask it to do an additional task (deal with stress, move a lot, lift things, exercise, work, etc.) it has to divide up its resources so each of the tasks gets a little less power behind it.

The best way to heal is to take things slow, get lots of rest and fluids, and try to reduce stress. Once you're done healing, your body can go back to its regular multitasking with no problem.

It hasn't in my case.... I had a total stress-ball meltdown a couple days after surgery (crying & hyperventilating for 5 hours, etc), and totally overdid it walking too much the first few days... That said, my weight loss has been great. Knock on wood...