Please help!

I have an almost 12 week old and keep getting different advice on how I should be breastfeeding.

I was told to do 5 minutes on one breast and then burp her and then 5 more on the other breast and then burp her and if she isn’t content then offer her the breast again. I’ve also heard I should let her go until she unlatches by herself. I feel like she spits up a lot even after burping her in between. I even tried burping her after 2 mins but that only seemed to make her mad and she never burped that way. If I let her go as long as she wants on the second breast, she never actually unlatches. She just falls asleep and uses me as a pacifier. No swallowing or anything just light sucking. I would like to try and do it where she unlatches herself so I know for sure she is done but quite sure how. When I do the 5 and 5 she’s content pretty much every time but still spits up a lot