19, hard to get/maintain erection, low sex drive, try to stay active but always sleepy after meals, little to no chest hair/ patchy facial hair?

Get workup: At your young age, just getting a blood test for free testosterone may not be enough, you need a good workup to evaluate your pituitary system as well.

See Endocrinologist: A detailed endocrinology work-up with lab tests may be helpful to pinpoint the problem. The pituitary can be affected in certain disorders. For example, a pituitary tumor can have some of these same symptoms. It is good to work this up further.

This is serious: You need a full workup by a competent physician with some specialty interest. You describe social anxiety; if you have some disorder preventing you from becoming a complete man (XXY, pituitary adenoma, any of dozens of others), it's cruel to miss what may well be an underlying cause. Don't accept a workup that doesn't lead to a diagnosis that makes sense to you.