I quit a month ago, but should I submit anything to HR?

I quit a month ago, but should I submit anything to HR?

I was in a role in another department and was quite happy until I was forced ("promoted") into another department. I was extremely reluctant as this new department had a reputation for being "catty." Well, I became absolutely miserable. I worked alongside 2 other women behind a counter-type set-up, and my manager was BFF with my colleagues (it was surreal).

Prior to my move, I addressed my ambivalence to upper management (he was new to the company and worked remotely for many months in another state). He was supportive and I eventually did express my experience/issues months later. For a short while, things seemed to improve, but it was fleeting. I didn't realize it at the time, but my health declined to where I couldn't sleep, my stomach was constantly upset, and my blood pressure was off the charts (I chalked it up to age). Sure, the job was stressful, but to feel so unwelcome/not included was crushing. I'd never experienced this in any workplace.

There was another woman in my role (my age) who experienced the same unfortunate experience, and she moved to another department. I also became close with two people in HR, although one resigned a week before me, and the other was out on FMLA. I did not know what to do. My family and friends encouraged me to quit, but I did not have anything lined up (I was already looking elsewhere). And I sure as heck didn't want these women to get the best of me. I am stronger than that. Until I wasn't. During a meeting with my manager, I resigned and provided 2 week's notice. I was told that the next day would be my last, and that I'd be paid for the next 2 weeks.

I declined an exit interview, returned my laptop, etc. and left with my head held high. Others in the company I'd befriended reached out to ask what happened, etc. but I did not speak ill of anyone or the company whatsoever. Later, my HR "friend" who was still out, encouraged me to write something for my file. I didn't see the wisdom in turning in anything. How could I prove that I was felt unwelcome or undertrained/set up to fail? No, it was not worth it as I would just come across as a disgruntled worker. I just wanted to move on.

Although I'm honing new skills to get into another industry, I'm concerned that any potential employers would contact HR and find something amiss (with what, I'm not certain). I was a very good, dependable employee with a strong work ethic (ironically, my manager told this to me) yet I feel vulnerable. My first manager there retired and we worked together wonderfully, as I did with the rest of my team (the first role, that is). By the way, that team was comprised of women of all ages and there was never an issue.

Would there be any advantage (or disadvantage) to submit anything now? I honestly wondered if I was discriminated based on my age (as did the other woman who left). And/or the fact that I was an "intruder" to this clique of a department. Whatever the case, I wonder if I should do anything, or just leave it alone.

Thanks for reading all of this!