sesh

So really what if he does really change and becomes better? I guess you meant for good. Than what's the hurry to start believing it? Than you'll have all the time in the world to relax and start trusting him.
But, you feel you need to respond to it right away, and I'm sure it's since you're aware this is not a lasting thing, so you're dragging yourself back into that vicious circle.
I don't think that kind of change is an instant thing, but even if it was what power you have over it?
I believe the problem is here: You feel just maybe this time it can be real, and you're afraid if you don't show your appriciation you'll miss out on oportunity for having a changed, better H.
You know it doesn't work that way. If he's really about to change, than he'll do it regardless of the way you react to it. I know you know this, but it's hard to stop hoping: maybe this time. I was were you are for the longest time ever.
You need start thinking about yourself. Don't let your happiness depend on anyone but you. I know it's much easier said than done, but it can be done, requires a lot of hard work on yourself but it can be done, and once it is done you're done with all the BS in your life, and you start waking up in the morning with a big smile on your face, and his changing or not becomes his business exclusively. Please, try to remember he's only a part of your life, and how big of a part should depend only on how much of it he deserves, based on permanent actions, not occasional good few days.
I wish you well
Hugs