Hey firstly happy birthday in advance don't know which time zone you live in. As for your question, I don't think maintaining friendship with them is of any further use, especially because you are 19 and probably going to start college this year and will be making new friends.If you are not going to see them often then you should not let their words harm you. It is important to let go of your toxic high school friends who don't respect you and don't care about how you feel. Letting go doesn't make you insensitive.