How big is your dental class? This is one 'con' for the small ~60 student dental classes (if you consider it a con like I do) is that it provides less opportunity to meet people like yourself compared to the larger 100+ classes. This is especially true if you come from a large high school / undergraduate institution where you have the ability to meet friends out of 100s, maybe even 1000s, of students.
I am entering dental school next year, and I'm married/older so it's a little different for me, but my brother had a similar issue going to a small private school.
Have you tried joining any of the student organizations? Volunteer groups? These groups will provide plenty of opportunity to bond. You just have to continue to step outside your comfort zone until you mesh with someone. With that said, don't change who you are to meet people; maintain your same values, goals, and character or you will just be kidding yourself.
I'm glad that you are able to acknowledge your issue and are seeking help early. This shows a lot of bravery and initiative. I'll have a drink with you if you're a D2 at the school I attend next fall! Good luck and keep your head up.