Hey there, Heyitsmeeee,
Welcome to the site. I don't know if I should be telling you this because your introduction also contains some friendly questions, but usually you can place your first introductions here:
https://www.adisc.org/forum/forumdisplay.php/3-Greetings-Introductions
Don't worry about that though, as I said, your post is a bit of a grey area, part introduction and question, also, I'll let you in on a secret, I missed the Greetings and Introductions section when I first joined late last year, so you're not alone in bypassing that and posting to this section first
Telling others can be hard, I've told some close friends and they are all accepting. I haven't told, nor do I want to tell my parents, my Mother is not very understanding, she found my stash once and threw everything away. If you feel your parents are open-minded enough maybe you can tell them, but if you want to get it off your chest, you can tell some close friends if you have good rapport with them. You can also bring any diaper concerns you have to your pals here at ADISC.
Wearing for the first time can be a mixed bag, especially if, like you said, you build up your expectations of what a diaper will feel like too much and then when you finally buy some, it's nothing like you imagined. Store-bought brands are never very good, but sadly, they're are usually what we all use our first time around. If your first experience didn't meet your expectations, don't be discouraged, my first dozen times wearing never fully lived up to my expectations and yet, here I am, in my late twenties, no longer a teenager and I still enjoy my diapers with my ABDL fantasies always living up to my expectations. If you want to get more comfortable with yourself and arrive at a more ideal experience, I'd definitely suggest either wearing more consistently or investing in some high-end adult diapers or ABDL marketed diapers, that is if you have the money and a way of securing them without getting caught.
Your struggles with wetting are quite common as well. I always had trouble wetting and messing when I started out. It's something to do with how your brain/body works and thinks after potty-training. Your mind says it's OK to go, but your body resists or vice versa, it's like a mental block. The only way to override it is to wear more frequently. Sitting on the toilet while diapered, something that you have tried, also helps in combatting the mental block. Even I have trouble with it from time to time, I can wet my diapers like a pro, but messing can still be occasionally difficult because of the block.
With regards to other things to do while diapered, that really depends on you. As an AB, I enjoy doing a bunch of babyish things while diapered, I play with my baby toys, I drink from my baba, I go down for naps. Of course, you seem to be strictly a DL so you might not have any interest in doing baby things while diapered. Maybe some of the other DL's on the site can chime in and give you suggestions. One thing I would suggest is maybe participating in some of your favourite interests while diapered. I have a DL friend who is an avid hiker and cyclist and I know he really enjoys doing both of those things while padded.
I hope this helps and I hope you enjoy your time on the site and make plenty of new friends