First off, I want to say that I'm so sorry you're in this position. I'm sorry he's abused your trust. I don't think anyone here is about to judge someone based on how old they were when they got married. There are some recovering addicts on this board who are teens and who have the wisdom of the ages.
You can't control him or keep him from using. You throw it out, he'll get it somewhere else, or he'll start to use the street version (Meth) as my husband did and that's not a road he ever ever wants to go down. Adderall is basically legalized speed (same with Ritalin.)
Some people experience a severe increase in their sex drive while on speed.
I have to agree with CW is saying, you cannot do this alone. This is pretty big. It's big for each and every one of us and the reason we come here is because we've admitted to ourselves that we can't do this w/o help. Consider a therapist yourself, or al-anon (or naranon.)
You can't think "short term" at this point, I'm afraid. It can't be "should I kick him out for a week?" That is a band-aid at best. You have to sit down and think about what you are going to allow in your life and what you simply will not tolerate, and then you have to stick to that plan--even if it means he's "kicked out" for a whole lot longer than a week.
This problem can't be wrapped up into a nice, tidy little package. It's messy. It's VERY messy and it has tentacles that will touch every single aspect of his and your life. You can't control that, but you can control exactly how you react and what YOU do.
As for your parents, your mother already knows. If she knows he's stolen her medication, she knows he has a problem--whether or not she's actually saying this to you.
His parents? That's a tough one and that's entirely up to you. Maybe his parents are a very bad influence on his life and he has an unhealthy relationship with them. I don't know. Families can be great on the outside, but hide some serious underlying issues that they refuse to face or deal with. (called: Denial!)
Again, you need to figure out what you are willing to live with and what you aren't then stick to your guns.
Has he admitted to having a problem? Will he consider rehab? A 12 step program? A therapist who knows his addiction issues?
Here is a post I made a while back with some info on it. Maybe it will help. I will state right now that many who get to this point have made peace with themselves and the fact that their loved one is an addict. They've put the power into God's hands, so to say:
LINK (Just when I was starting to trust him again..)
God bless