I have some advice and tips for recovery but just remember everyones different and my advice may not be helpful as everyones different in recovering but it could be and i hope it helps in some way. Please dont be discouraged youve had a relapse in dp. For alot of people, you can go in and out of it and alot of times while recovering, you will have relapses but the fact that you were able to feel normal again is a great sign! I also dont know if i ever became fully recovered myself since im still plagued with existential/philosophical thoughts but most of the other symptoms of dp for me disapeared and only reappear when im really stressed so as someone whos at least mostly recovered, heres some of my tips:
-try seeing a therapist, espessially before you possibly get worse, ones that specialize in dissociation, depression, existential issues and ocd are the best ones for this type of thing
-research dissociation as a illness and try and figure out why you have it. If theres a reason for why its occuring, then you can tackle whatever is causing it in you, for example: depression and grief was the cause for mine.
-reach out to your family or possibly friends if your close enough to them. People can have good insight and help you see in a different perspective with certain things, also it can help to know if someone you know has ever experianced similar things than you.
-get a journal or something to write or type out your thoughts so your mind can make sense of the thoughts going around your head.
-this is a important one but get out as much as you can and do things that stimulate your mind like hobbies or games or whatever has made you happy in life because it helps you think more positivly and helps you stay out of your head when its just circulating all those horrible dp feelings and thoughts around endlessly and when your back home, it makes it a little easier to tackle your dp when it gets worse again. Though some days, despite going out or doing things, you might not feel the dp has gone away at all but dont be discouraged, you just gotta be consistent and youll start having better days.
I probably have more that helped me but i cant think of anymore right now but i hope this helps.