If you feel like you are headed to stressed/depressed, I'd say WTA juices MIGHT help you. It's probably your brain adjusting to the lack of MAOI A and B action that's in alkaloids (and even tar, although I seriously don't recommend returning to smoking). You can get low nic wholesale WTA, I think umbavape will sell it low, like 3 mg nic.
With that said, I'd probably have a hard time bouncing around from 0 nic to some nic. Why not pick a strength to just go with? I mean, nicotine is a stimulant as well and has some antidepressant action, so it's possible that all the bouncing around might be stressing out your brain as well.
I will say also, that in terms of adjusting to your brain's homeostasis, picking up WTA may delay that depression/stress feeling, but it will also keep your brain in that cycle, versus detoxing fully and letting your brain adjust to normalcy. A lot of quit smoking drugs are actually antidepressants first... Like Zyban, that's a "quitting" drug that's really an AD.
Also (probably unpopularly for you) nicotine is a stimulant so why wait to start exercise/weight loss for when it will actually be HARDER, and you will be gaining weight more easily? Exercise IS a powerful antidepressant, probably best not to wait to start it until you are at your lowest?
Just my thoughts, as always. I am injured right now which never happens, and I find myself super cranky without my daily endorphin rush....
Good luck with whatever you decide.
Anna