I think what has happened is that you said you have been ‘casually dating’ this guy for 3 months, but you are in-fact hooked and chasing him down for a relationship that isn’t ‘casual’. Only, you’re not getting what you want.
I’m paying a lot of notice to the fact that it’s you asking him if he wants to see you. It’s like you are
literally begging him to throw you some emotional crumbs. In my personal experience, there is only one reason for the symptoms you are describing and that is you are involved in the early stages of a toxic relationship.
Your head is in a mess? Yep. That’s because he is blowing hot and cold on you. This is a control and manipulation tactic. And guess what, this is the tip of the iceberg of how bad it can get.
You’re becoming a nervous wreck over whether or not he is into you or wants you and it’s not making you feel good. I don’t know if you have had relationships before where this level of anxiety sets in so early, but I have. It’s not a good anxiety is it? It’s that doesn’t feel good anxiety isn’t it. This is a warning sign. A red flag. It means the balance of the relationship is out of whack and it’s not in your favour. Your symptoms are almost like that of a drug addict, where unless you get some sort of emotional crack from this guy, you’ll go into withdrawal. Which is, essentially what you are experiencing now i’d say and he knows.
I think this is the beginnings of a toxic relationship and possibly an abusive relationship where you will be the victim and he the perpetrator.
I personally think you should turn around and walk in the other direction now, before it’s too late. Block the number. Sit on your hands. Don’t make any more contact in any way. This feeling will pass with a little time, please do not give in to it.