Did I scare her off?

Hi!

This will be a lot to read so I appreciate if you could take your time and read everything. To make it easier the girl I'm dating is Kriss. The guy you are going to read is Tobbe and the girl who hosted the party is Julia.

I have been dating this girl since the start of 2018. She is 17 and will be 18 in a few weeks, while I am 22 years old. Most of my friends give me hate because I should not date a younger woman. All I ask for is help and not hate. It is two things that are bothering me. Also I have not been in this situation before so I don't know what to do and how to react.

She invited me to a party, but I told her I would be late cause I had other things to do. So while the party was going on she sends me a video on snapchat of her playing with tobbe's hair. For me that was not okay. Imagine If I wasn't there she could have slept with him or if not being intimate. She even said that she once slept with him at a party hosted by Julia. (She ment the party that was a while ago, not the party that was last night.) so clearly Julia had hosted a lot of parties.

Now when the party was over everyone went to bed and I slept besides Kriss. Kriss was stroking me by my arm, and wanted me often by her side. I did not make a move or take her clothes off it just got intimate. So in the morning she used her foot to push me aside which I take it as I was too close on her or that she didn't feel comfortable with me.

Here is what I'm thinking. She might test me of how far she can go before making me jealous. And are Tobbe still having sex with Kriss? Why are Kriss acting like that now when she was not like this before?

Also It could be just me overthinking because we're not sure if Tobbe and Kriss is still sleeping together and maybe them playing with each others hair is a friend thing. I won't jump to conclussion too fast.

One thing is for sure... I will not say sorry because then I come across as too insecure and that turns her off. Do you have any advice on what I could do?