Amatriptyline works well for a lot of people; for me the side effects stopped me from taking it on day 2, and I am now trialling Pizotifen which seems to be helping (only a week in though).
Yes, it is a horrible thing to go through, especially when you are only 20, but for me the biggest single improvement came when I accepted the fact I had an illness and that I had to allow myself to be ill, and allow myself and my body to get better in time.
It is hard when it is a weird condition like MAV, but you're not losing your mind, and there is a lot you can do to avoid depression. Remember, you only have to do one day at a time. Think: what can I do to make today as good as I can? Don't think what you can't do, think what you can do. and do some of the good stuff. find things you can enjoy now, and do them.
for me, MAV has been like getting hit by a truck and falling into a timewarp. I spent ages freaking out, thinking WTF happened, but when i finally found out I had been hit by the big gnarly MAV truck, but that I was still alive and can still make a full recovery, it seemed to take a huge chunk of the stress away. i'm not better yet, but i'm not freaking out, and the freaking out was at least as bad as the MAV, maybe much worse.
Don't beat yourself up about what you can't do for now. Just allow yourself to get better.
If you had been hit by an actual truck, you wouldn't try to force yourself to get better quicker than it takes. MAV is the same. you can get better but it takes time.
Good luck, and let me know if I can help.