Yes. All of the above.
I'm glad you were decisive.
It's hard not to analyze but THIS is EXACTLY where you need to be. Just keep quietly observing him and examining your thought processes. Recognize fear if and when it arises. Recognize similarities in how your brain thinks in this relationship and in prior relationships.
You can observe and say nothing and do nothing in response. Make it practice in inhibiting a reaction. Feel the feelings, notice what they are doing, feel them leave you, remain separate from them. As though they are moving thru you, but are not YOU.
Anyway sounds hokey but that's what I'm doing. Heck normally I'd be panicking and throwing a panic tantrum or something in response to some things so just try to look at yourself and compare you now to you in last relationship.
Slow your brain down some. He sounds OK so far.