Keep in my abid that the first “shot” of Dhamma is really life changing for many people, my couple of weeks when I found pure Dhamma and discourses, I was like Anagami (no desire, can not get mad, can not get sad, just clarity and wisdom that got even people interested in that change) but after a while a lot of things will come back, as this is just start of the way. To get this stage permanently, there is a whole process that may take a lifetime or a couple of lifetimes before you can achieve it. So do not worry if that happens, do not panic and do not think “there is something wrong with me” etc. it is good to be aware of it. You will need to find new ways to develop insight, new terms, new wisdom that will step by step dissolve ignorance
Yes you described my experience well I am kind of disappointed in myself for slipping back to old ways after experiencing and feeling the blissful clarity Buddha Dhamma gave me. I just need to move forward on the path now somehow. Once I’ve learnt all the foundational knowledge from reading + desanas, i begin serious formal meditations and contemplation work
I just need to take consistent, patient action every day.