RE: Relationship Advice

I have a wealth of questions with respect to this whole area, so any advice or discussion would be greatly appreciated.

I am new to figuring out what being autistic actually means, having gone from being a suspected autist to fully diagnosed in the space of a year. I have had my fair share of incredibly unhealthy relationships (not helped by my undiagnosed autism, no doubt), and I now find myself with a partner who I worry feels I am not good enough for her.  I can't really tell whether or not it was the feeling safe enough to unmask, or whether the relationship has been so tough I found myself thinking I was going insane that led to my diagnosis but here come the questions;

Am I inadvertently being emotionally coercive/abusive by making my partner feel unsafe/insecure/under appreciated?

How do I get better at listening/expressing love in the way she needs me to?

How do I know whether or not this relationship is the right thing or the wrong thing for me?

Is it just me that messes up and apologises, tries to better their behaviour just to continue to not do things 'right'? 

How many "I'm sorry"'s is too many? Am I lazy or incompetent to change? 

I realise what I really need is a therapist, but finding one that ticks all the right boxes these days is not only rare, but incredibly expensive when they do come around. I also realise that this has rapidly spiralled into an Agony Aunt-esque cry for help, but I'm not embarrassed by it. Not really sure how to sign off but thanks for reading if you made it this far!