Are there other 18 year olds who deal with sleep apnea, major stress, high blood pressure, low testosterone, and more? im so scared for my future

Yes there are: Hope u have good internist, are on c-pap, on strict weight reduction diet if overweight, low salt diet, antihypertensive, possibly anti-anxiety medication, in counselling & getting lots of exercise. Also trainer at a health club might be a good idea! good luck.

Yes: Unfortunately, it is becoming more and more common, particularly as obesity becomes more common in your population. I'm going to assume that you're very overweight and you need to consult your doctor for all of these problems - and lose weight.