I have no experience with romantic relationships (I'm not even sure about strong platonic relationships, for that matter). I am possibly interested in changing this. As a hint at some almost-definitely-harmful things that I haven't been able to remove from my mind, the previous statement was far more painful to write than those before it (as in, if I wound up in a romantic relationship, I would absolutely dread discovery from my parents, knowing that the worst they'd do is make comments intended to be humorous rather than harmful.).

I want to commend you for this. The signaling of saying "my love life & romantic experiences are bad I want it to be better" is bad and there is stigma attached to trying to publicly saying you want to fix it. Let alone doing anything that might actually fix it! Yet it kind of is what you have to do.

I walked a very similar road of self-improvement several years ago and it also started with the painful admission to myself and then to others that I wasn't doing as well as I wanted.

Beware far mode well meaning advice people will give you on romantic relationships and sexuality. Much of regular advice is almost anti-knowledge.