Well. If your parents keep you from Mass, then it isn’t your sin. You aren’t culpable for what isn’t your choice.
As for confession and Mass… I have an idea. The first is this: most parishes I know have confession and then Mass. For instance, confession starts at 4PM on Saturday evening, and extends until the 5PM mass. This is probably your best bet. Ask your parents to drop you off early for Mass, go to confession and then to Mass. Since confessional lines are typically short (sadly) it shouldn’t be a problem. If the line is long and you’re running out of time, then if you kindly inform people of your plight, they’ll probably be receptive to letting you go first.
My second idea would be to catch a priest before or after Mass to have confession. It may be somewhat difficult, but it’s always worth a try.
But my overall point would be this: be persistent. Keep up trying to get to Mass or confession as often as you can, and
pray for yourself and your parents that their hearts and minds may change.
Besides, most parents I know do tend to like their children, and if they see that this is what
you really want, then after a while they may decide to let you do it. After all, you’re not doing drugs or anything.

It takes some parents a while to get used to kids who wear dark clothing, and crazy makeup and hair. It may take time for your parents to get used to a kid who keeps the faith. But by all means, keep the faith! Best of luck!
-Rob