How to stop overthinking new boyfriend?

I'm going to apologize because this is a bit long and I just really wanted to put this out there. If you have any advice on how to not over think everything, please help!

To start off, we're both young adults (I'm 19, he's 20).

I've been seeing this guy for about a month, in which we essentially spent all of our free time together before last week when I officially asked him out - he said yes. We spent an odd portion of our time together strongly hinting at a relationship starting so it wasn't really a big deal to take the next step and ask him out.

We're different in a few ways, but nothing that's earth-shattering. I have (had, kind of) a really set plan for my future and I put a lot of thought into everything I do... you know, 'everything has a reason' etc. He just kind of goes with the flow, he has ideas of what he wants but isn't actively pushing towards them yet which is fine because we're both young. I'm ahead of the game, really, and I don't expect other guys my age to be.

I'm a virgin. That isn't an issue to me, or to him. Sex isn't something I have any interest in and he knows that and respects that (everyone in my life jokes that I'm asexual, that's how disinterested I am). He had quite the promiscuous stage that apparently abruptly ended once he met me - I believe that, because we were together too much for him to sleep with other people without me finding out. It wouldn't have concerned me anyway since we weren't exclusive at the time that he was telling me. But, his sexual experience kind of throws me off sometimes.

I'm not a prude. I believe that sex feels good and I think if someone wants to share themselves with anyone they can, they have every right to. I don't believe in sluts or skanks or anything like that. I just never did that since my sex drive is stuck at 0, so I literally had no reason to pursue sexual relationships. But now that I'm in a relationship with this guy, and my feelings for him are stupidly strong, I'm beginning to feel a bit overwhelmed by his experience. And not just sexually, but with guys in general - he always has a story about "this one guy he was with" and I just kind of have to sit there and nod and laugh and then wonder about it.

We're quite different in that sense, and it stresses me out a bit. I trust that he likes me - I really do, but I still can't help but feel like a number sometimes. He doesn't do anything specifically to make me feel that way, it's just that he's very open about sexuality and his past and I have nothing to be open about, so I feel a bit indirectly inferior in that sense.

So then I get concerned, wonder if he really does like me (out of the... large amount of people he's been with he's only had about two other proper boyfriends, so I'm number three) but then since I'm only his third proper boyfriend out of all the people he's been with (sexually and not!) I feel kind of good because I assume he does really like me.

I have one ex, who was insane and really clingy and needy and would constantly validate why I'm so fantastic. I didn't like it. Now that my new boyfriend doesn't do that, I get confused and wonder if he really does like me! I don't have any self-esteem issues, at least not personality wise, so I don't know why I feel like I need that validation. I trust him. I like him. He likes and trusts me.

What's my fucking problem?!?!