My thought is that a junior college with a track program would be a solid and affordable route. My suggestion is not based on your academic stats, but on the combination of stats + financial constraints (extremely important in college considerations).
First, while you have good stats, they’re not in the merit scholarship range that would make 4 year university affordable. From the tone of your posts, it sounds like you’re going to get little or no help with paying for college, and merit aid is needed not just desired.
Second, while a gap year might give you opportunity to take more SAT/ACT tests for a higher score, you’re going to be applying with the same academic record and GPA that you end high school with. Mathematically, it is highly improbable that, by the end of your senior year, your unweighted GPA is going to be significantly improved, and colleges aren’t going to be disproportionately impressed by your ability to get a high score on an insular test(s) that tests your ability to take that test. A gap year should be about doing something meaningful, and impactful. And/or, about saving money to pay for college. There are options where junior colleges have dorms, and sports team, and where you might get a full ride. So, you could work, and pocket money for when you transfer.
Third, if you really want to run track in college, a gap year is not advisable. If D1 schools have not recruited you by now, it is highly improbable (not impossible, but they’ll have made their commitments by the time track season rolls around) that you’re going to get senior year offers/commitments, let alone post-high school interest. And, it’s likely that you’ll be too old for AAU track once you’ve graduated high school, so where would you compete to demonstrate that you’ve reached D1 capability? Schools aren’t going to take your word for it.
Going to a junior college might very well turn out to be free for you, with your stats, and would allow you more time to develop, while remaining recruitable, IF you reach D1 times/marks. It would also give you the opportunity to perform at a higher level academically. You said that you’re willing to work hard(er) in college, and that’s important. Results matter. Not what you’re willing to do, but what you actually demonstrate.
Finally, I’d like to echo the sentiment that everyone else has. Financial aid was never going to be a magic bullet for funding college for you, so your mother getting married didn’t take something away from you that you had a right to expect. And, your future is in your hands, not your mother’s. As someone above already mentioned, college selection (and I’ll take it a step further and include post-high school direction, period) is, more often than not, about what you can afford. You’ve got viable options. They may not meet your desires for today, but as a young adult, you have to realize that we don’t always get what we want, when we want it. Still, you can have a future that results in a college degree.