Your example doesn't qualify based on numerous reasons.
1. It is unknown if she actually would have gone out on a date with you. Even if she had gone out on a date with you, the whole interaction might have been 1-2 sexless dates and no LTR. You also likely overrated her signals. It's common for even neurotypical men to overrate most women's signals.
2. You have had sex with 9 different women from the conventional mating market since this happened. You were never able to build momentum off of those 9 different women. I don't think this would have been any different under the highly unlikely, best case scenario.
3. You are on the autism spectrum and that makes it difficult to be successful with attracting, seducing, and retaining women.
It is true that all men will have some woman in their lives that they wish they had pursued. This is even true if they didn't get any IOIs from a woman. In high school, there were girls on the cheer/dance team that I wish I had pursued. Some of these females didn't even show me the slightest IOI. In high school, a cheer/dance team consists of the highest social standing and some of the best looking females in the school. It's a good idea to take your shot with as many of them as possible.
Many men do look back at times and lament the missed opportunity. It's best not to dwell on it. I haven't dwelled on any cheer/dance girls that I didn't ask out back in high school. I have occasionally checked the social media profiles of a few of the cheer girls and have seen instances of declining looks.
The solution to this issue can be boiled down to a quote from Rollo Tomassi.
"Money, muscles, and game"
Muscles are the best solution to opportunities with women, especially under age 35-40. Looks are the #1 factor in seduction. Building a great physique will create opportunities. Women might show more IOIs pre-approach, women might swipe right more often, and women might also accept more date offers due to a good physique. Focus on building muscle.
@BPH has been successful with women because of his physique (and to a lesser extent, personality).
Game refers to elements of personality. It is your charisma, risk taking in making the approach, etc. There are always opportunities to improve.
Money isn't something I need to explain.
If a man does well on money, muscles, and game, he will miss few opportunities and he will have more opportunities.
Money, muscles, and game.