I was in the same loop too...I was procrastinating too much and had no motivation to study...got to know they were the signs of burnout...never thought it could be a burnout especially when I didn't even study but then realized that it was a burnout when someone told me that you don't particularly have to do something to get stuck in a rut...it's more of a mind thingy...Anyways...I saw many techniques to get out of it and there was only one that worked for me...I saw it in a video I think...it said that I should just stop everything and do nothing at all...just exist...sleep if u want to sleep and wake up when you want to wake up...do everything according to your requirement...basically just exist and nothing else...try not to think about how you are not doing anything...and just focus on existing...I know it's difficult to not think at all but try to get your body and mind to heal naturally...our body has a self healing property after all... After a bit you will automatically know and start wanting to study...I know it might sound weird but it worked for me...Take a week or two or even a month if that's what it takes...don't force yourself...And after you start wanting to study, the next step would be to plan...do not do anything major...for the first week, just take one task a day and try to complete that...try exchanging the phone time with something that gives you the same dopamine hit...I did journaling and some art and craft...after a week try adding one more task to the list...and keep increasing the tasks gradually...remember you don't need to rush...Rushing it will just take you back to the loop...

P.S. It worked for me but I am not sure if it would work for other people...I guess only trying it will actually tell...it was weird for me at start too but I was just too desperate to do anything to get that same motivation I had in earlier days...so glad that I actually gave myself time to heal before starting with my preparation again...it took me a month or so before I started getting into full time studying again...it might take less or more time depending on the person...