Thanks to everyone who replied! It's been really helpful.

Quarter life: Well put, seriously. Good news is that I have a tabletop gaming group that's every other week, which has allowed me to at least connect with people who are pretty much interested in the same stuff I am. And participate in tabletop gaming, which is awesome. So I've definitely made that step.

Shy Introvert: Thanks! I'll definitely look up some stuff in regards to saying no to people and letting down my walls. As for books...well, I'll have to take a look out for those. And yeah, you're pretty much spot on. My mom actually said that when she took me to a psychologist as a kid, they said I was kind of a people pleaser (I must have been like, eight at the time). And yeah, I guess I do fear rejection. I guess I also have my share of abandonment issues, like "what if I mess up and this person ditches me." But yeah, baby steps sounds like a good idea. I can at least practice.

Healingme4me: Thanks! I'll definitely go and take a look at what's out there.