I went through some of the same experiences, so you are not alone. I was in diapers until age 3 on a regular basis and I can even remember my parents friends picking on me. I would feel self conscious having my diaper changed in front of them. Mostly though I was a heavy sleeper, which meant bed wetter. Up until the age of 8 my mom would diaper me every night. I remember hating it, but if I went to a friends house I always wet their bed, so I didn't do many sleepovers.
My sisters always made fun of me for this and still bring it up today, 16 years later. Sometime between 8 and 9 my mom stopped diapering me at night, just randomly. She never said why and never mentioned why, just one night it stopped. It was weird because I hated it all those years, but soon after I missed diapers. This went on for about four years, where I occasionally would look for diapers in the house.
Finally at the age of 12 I found the right opportunity to buy diapers while my parents were in another store. I had a key to the car so I ran them back to the car and hide them. The whole way home I feared they would find them, but I was very excited too. Finally snuck them up to my room and put one on as I started to get "excited" at the smell, look, and feel of a fresh diaper. I put one on, laid down, and rubbed myself on my mattress, bringing myself to my first ever orgasm.
It scared me to death, but ended up loving diapers from there on out and have not stopped since. So a late potty trainer, bed wetter, turned into a diaper lover. Almost got caught a couple of times, but mom played it off well thankfully. I think she knew for some years though, finding websites like this online and randomly finding diapers.