Is a guy showing a bit of emotion unattractive? How do girls feel about insecurity in guys?

Anonymous
So for some context, I was dating this girl for around 3 months, to me it seemed like everything was going well, she was always quite busy and so was I with work so we really only texted in the evening and met up at the weekend.
I'm a big believer in the slow burn, and even though this girl was not my type at all, I just loved our conversation, how smart she was. So many things, that I could really see a future.

Eventually we have sex, kiss etc but it comes out that even though she thinks I'm ambitious, intelligent, adventurous, easy to talk to etc, she didn't feel like we had enough chemistry.

I felt a bit deflated after this, since by this point I was really starting to like her and could really see it working out. That same day I opened hinge (hadn't been on in a good while) and noticed she had updated some pics.
Also previously while in bed together, she showed me something on her phone and had a hinge message.
So I sent her a message saying I was a little upset, since we had slept together I just assumed we wouldn't try and date anyone else.
She interpreted this as me trying to tie her down into a relationship, stalking her, not trusting her and said that she wasn't dating anyone else but she had chatted to two guys before we slept together which had stopped.
We had a few more really long discussions over text, she mentioned the chemistry issue a couple more times, how it goes going to slow, but because of the connection she asked if it could it be salvaged.
In summary I replied, if it's my appearance then there isn't much we could do, but if it was the "magic" then that could grow with time. And if she wanted she was free to date other people, it's her life and her choice. She never replied since 2 days ago.

Was it a mistake to say she could date other guys? Would this come across as if I didn't care/insecure?
Is it unattractive if a guy gets insecure and shows emotion with his partner?
How do you guys feel about arguing over text?
Is a guy showing a bit of emotion unattractive? How do girls feel about insecurity in guys?
2 Opinion