Hi!
I'm sorry to hear that you've had a hard time! It's absolutely never too late to turn things around, whether that be this year for yourself or taking another gap year and using it very intentionally. It sounds like having a target + time would be good for you, so you have something to focus on and a timed goal.
It's never too late! And keep in mind that some courses can be 3, 4 or even 5 years, so even students that started at 18 may still graduate at the same time as you would. I personally took a gap year then graduated at 22, and I have a close friend that's just started this year at 22. It's good to keep in mind that your age isn't stamped on your forehead at uni- and you have lots of time to do what you want in life!