Waking up with arrhythmia/heart racing / sweating. could it be sleep apnea? if so what can i do to fix it without a sleep study? i'm only 23

Need sleep study: You definitely need a sleep study to rule out sleep apnea. This can be a cause of symptoms and is managed in many different ways. Non surgical, surgical, weight loss and others. If nit sleep apnea, need to have a full work up to rule out cardiac or other systemic etiologies.

Sleep apnea: If you are overweight, losing weight not only reduces pressure on the airways, the tongue shrinks in size, further opening the airway. Don't sleep on your back ( sew a pocket in a t-shirt and put a tennis ball in it ). See an ENT to make sure that there isn't a problem with deviated septum, tonsils or adenoids. Use breathe rite strips. See a dentist to have a custom sleep device made.