If anything I feel like becoming more emotionally mature opened up my dating pool, and made me a better partner. Ultimately you are better off being with someone who you can talk about your emotions with.

I've been in relationships where I couldn't talk about my problems, and being unable to talk about them didn't make those problems disappear.

Yes, very much worth it. As someone who divorced after two decades, living your life behind a mask isn’t worth it for any romantic relationship. Which will lack true intimacy, since you will not be known for who you are. You will never feel chosen just for being you, because she won’t know who that is.

I get open and vulnerable and emotional with my partner, and I have since the beginning. Hasn’t hurt things yet. Maybe that’s still coming, but again, I’d rather be single.

Is this even a question? 1000%

Emotional vulnerability and openness is predicated on trust. If you can't trust your partner to be there when you express yourself, then you have a serious problem. Trust is the cornerstone of any relationship.