If i was around 185 ish at 5'9 and now i'm 170, does this mean my sleep apnea could be gone or do i need to lose more? i'm 18 male

There are different : Reasons for sleep apnea. It would depend on the cause of your sleep apnea.

Sleep apnea: If you had an overnight sleep study and that was the reason for the sleep apnea diagnosis, having another study is the only way to determine whether you are "cured".

Symptoms?: What are/were your OSA symptoms? Most commonly would be daytime sleepiness. Still present? Then perhaps weight loss would make a difference. There are other factors to consider. Only "proof" would be another sleep study.