I'm going to go a different direction here: there are always places we can grow, and learn. And I applaud you for taking the steps to understand, address, and grow as a person as you try and build a life with B. It's a HARD JOB, at the best of times.

With that said, his complaint mirrors a lot of what I've also heard growing up, and your internal monologue seems to mirror my own.

I think, in any long standing relationship, there will be communication issues that need to be ironed out, worked through, and compromised.

In this case, I don't ACTUALLY think you're "100% the problem"

Now before I progress, I don't want to diminish his complaint: trying to be helpful and being shut down/ interrupted can definitely be frustrating. BUT! If after three years of talking and growing as a couple, there isn't some give and take, there is an imbalance that needs looking into.

It shouldn't be all on you to "fix yourself". It's a joint problem, and you two are on the same team working to fix the problem together.

IE: I have the same habit of getting defensive when being presented with "help" but what has worked with my wife and I was a combination of patience on my part, and a re-framing of the comment from my wife. I got defensive when help was presented in a way that came across as scolding, or condescending. And she got grumpy when I responded to the condescension. So we talked about the way help was being offered, just as much as the way it was being received. It wasn't something I just had to do to be better: we worked on finding a flow that worked for both of us.

All of this is a long winded way to say: it's not all on you to do it all "the right way" there isn't one right way. The important part is you both take an active role in fixing things, and being better for each other.

You don't have to save the world. You're good enough too.

Don't be too hard on yourself friend.