Welcome to the Nexus!
Did you check out our health and safety section? The integration part has some good tips.
I think that if you go back to your old life and you keep everything exactly the same, it can indeed happen that you tend to fall back into at least some of the old possibly negative habits. So if I were you I would use the opportunity when you come back and change things physically so that symbolically/psychogically it can help you. Maybe moving to another home, or just adding something to your room, or also some change in your daily schedule, adding some specific thing like a new hobbie/exercise or a change in diet, whatever. Then you can somehow "anchor" yourself in the change and take together the other positive changes you want to make.
I dont know, just something that came to my mind..
As for letting go, breathing and remembering "This Too Shall Pass", detaching from judgement of things that might seem harsh or negative, is how I do usually it for myself, but you'll have to figure your own way. Youll see that holding on will just lead to more pain, letting go is the natural way.
I wish you well on dealing with the issues you have to deal with. Maybe ayahuasca will give you want you want, but maybe it will give you something else entirely. Regardless, your path will continue once youre back, and I hope you keep strong in it, always learning, always trying to be more aware.
See you around!