I’ve had orthodontic treatment since the first year of middle school,

Hello :-) I started orthodontic treatment in my first year of middle school and had it for about 5 years, but my teeth are shifting back ㅠㅠ The dental clinic I used to go to for orthodontics closed down midway.. So I kept wearing the fixed retainer(?) inside, but it got so yellow that I went to another dental clinic and had it removed. Now my lower teeth are going back to their original positions ㅠㅠ In this situation, would it be better to get orthodontic treatment again? I had braces, but my protruding mouth didn’t improve either,, and it cost 3.6 million won at the timeㅜㅠ I’m so upset