When do you know if a relationship is right?

I've recently starting dating again after being married for a long time. We've been together about 6 months and it had been going well but it feels like the energy has changed. I'm starting to really question whether it's because we're just not on the same page or if it's all in my head due to feeling insecure after infidelity in my last relationship.

We have the same interests, really laugh together but I get anxious when things are quiet. Like I have to fill the space. Surely I should be comfortable just to be? And I worry I am running out of things to say.

I do find this time of year hard with the weather and low mood so wonder if it's all in my head and I should just let things play out but little behaviours have started to change my perceptions of how we are, nothing sinister at all, just a feeling of being thought of really. It's been so long since I've been in the throws of early relationship that I don't know if this is normal anymore...

I really care about the person I'm dating, so many great qualities but there are just niggles of doubt. However my last relationship was abusive so I have no idea if the lack of intensity is actually a good thing. And when I'm double guessing things is more my head than the actual situation.

We are forward planning things, we have similar hobbies and interests and generally really enjoy each other's company. I just don't want to invest too much if it's going to cause me anxiety.

Have no idea if this makes any sense. I do have audhd which can complicate how I view things.