Both of those sound like unproductive excuses
Usually when I’ve asked women if they wanted to go out with me, the responses have been “I am too busy.” and “I don’t think my boyfriend would like that.”
Those are normal "no" answers. They didn't want to date you.
It's very common for such refusals to include a plausible excuse as a defensive measure against the small minority of men who react badly to a refusal.
If you didn't know that already (or have ignored it when it comes up here), you urgently need to put some time into learning the basics.
Women in the culture I live in also tend to regularly have boyfriends as well as marry early.
This has really stacked the deck against me.
The M/F split among unattached people in your local environment should be approximately even.
Note that imbalances are fairly common (NYC supposedly has more unattached XX than XY, while places that pay well for physical labor are often XY-biased).
But if there's a significant bias in your community, it will be well known locally.
If you want to avoid your past looking like your future, you need to establish better objectives than "I want a GF", identify constraints and requirements, make a plan, and get to work on it.
BTW "past determining future" is more of an excuse than a useful perspective.
The past is a foundation. It influences your future, but doesn't control it.
And in your case you frequently say you want something you don't have, which implies you're hoping that your past doesn't predict your future.