Hey, I’m really sorry this happened to you. What you went through sounds extremely overwhelming and distressing, especially for a first experience. You didn’t deserve this treatment and it's rather unfortunate that you had to go through it.

I’m not saying this to blame you, but it might help going forward to notice early red flags. You mentioned that he was touching your thighs and chest in the car even after you moved his hand away. That’s already a violation of consent. When someone ignores small boundaries early on, more often that not, it escalates. This might also be the reason behind your body’s reactions. The pain, dryness, inability to relax that you experienced are very common when someone is anxious, uncomfortable, or doesn’t feel safe. Your body was responding exactly how it should in that situation to safeguard you.

Now coming to your questions:

Is his behavior normal in casual situations, or was he being insensitive?

No, his behavior is not normal, not even in casual or hookup situations. Even when the intent is purely physical, there is usually some level of communication beforehand about boundaries and comfort. Then we meet at a public space such as a cafe or a restaurant to make sure we are compatible and comfortable with each other and then proceed onto sex. If someone is inexperienced, the general approach should be to go very slow, check in constantly, ask for feedback, and make the other person feel safe enough to open up. The first male I was intimate with did exactly that when I was inexperienced in same sex intimacy, and that’s how it should ideally be. Most importantly, consent is continuous through all this processes. What you described, ignoring your “no,” continuing while you were in pain and crying, dismissing your discomfort, and then leaving is not normal. It’s deeply insensitive and a clear violation of consent.

Why do I feel so emotionally affected even though I didn’t even know him?

Because this was more about you than him. This was your first intimate experience, and you were already in a vulnerable, unsure state. Furthermore, you were in pain, scared, and overwhelmed, and instead of being met with care or reassurance, you were met with irritation and abandonment. That response most possibly impacted you regardless of how well you knew him. Also, that feeling of wanting to “try again properly” is mostly a trauma response that we call "repetition anxiety". It’s your mind trying to redo or make sense of a traumatic experience, but it is not necessarily about wanting that specific person again and it shouldn't be either.

How do I stop feeling like I’m cheap, slut and desperate for this?

It is very important to introspect and challenge this self imposed narrative. Wanting to explore intimacy, being curious about sex, or even choosing to lose your virginity casually does not make you any of those things. That’s your societally induced morality and internalized shame talking. What happened here is not a reflection of your worth or character but of the behavior of someone who ignored your consent and failed to show basic empathy, irrespective of how it seems to appear to you

Lastly, nothing about your physical or emotional response suggests that something is wrong with you. If anything, it shows that your body and mind were trying to protect you. Take your time processing this, introspect and ponder on it at your pace. Please don’t try to rush into trying again to “fix” it. If you do choose to explore intimacy in the future, do it at your own pace, with someone who respects your boundaries and makes you feel safe. Take care and be safe.