We are not able to diagnose anybody here but it does sound like you have a lot of traits of BPD. You are only 18 years old but I am sure it would put things in perspective for you. If you ever get overly "sensitive" fill a bowl of cold water and put ice into it, the colder the better. Dunk your face into it for 10 seconds at a time and do this repeatedly. It does help.
It works. I hope you find your way....

Best wishes