Concealing acne? Please help!!

Hello,
I'm a 17 year old male who has had moderate to severe Acne for about the last 3-4 years now. My family is struggling financially at the moment, so we can't really see a dermatologist (not to mention, I have no health insurance). However, things aren't as bad as they seem. My father is a doctor (a Neurologist/Neuropthalmologist), and while his expertise in Acne and skin care is limited, he does read many books and journals over every aspect of medicine, so he does know a fair amount. He's also able to prescribe medications for me (Clindamycin, Retin-a, etc), and I'm eternally thankful.

Anyway, the battle against my pimples is ongoing. But thats not really why I'm posting. You see, not only do I have about 3-4 pimles on my face usually, my skin has a terrible tendency to SCAR all the time! After every pimple just about! So i'm left with dark/purply marks on my face even after the zit is gone!
It is so embarrasing and frustrating, because few other people I know suffer from this problem like I do.
SOOOOO...I'm asking the people of this forum, male or female, adult or child, what is the best product to CONCEAL acne? My mother has tried different make-up she uses on me, and it works fairly well, but its also somewhat obvious I'm wearing make-up on close inspection. And it doesnt relaly cover very well.
Can anyone recommend a product that conceals pimples or scars well, without looking obvious??? I'm a guy here, so wearing make-up to school is somewhat...embarrasing..to say the least.
If ANYONE can make ANY recommendation to me about a good product to conceal Acne pimples or scars, I would be eternally grateful.
Farewell and thank you!

-Gordon