When I was a young'un my parents did the same thing to me. I had one D in my life and they made me see counselors and what-not. Don't get too mad at them, parents do a lot of silly things. After they fully understood why I got the D they were less mad but still upset I couldn't overcome and just teach myself. They D was in second year Honors Latin, my teacher was retiring and ranted the whole class on boycotting the movie Dogma and why he refused to sing songs in church that were too "pagan" in content. Not really much about Latin or verb conjugation or anything related to class. If you are so used to getting A's and B's, anything lower may concern your parents you know, like "he always does well, is he sad/distracted/uninterested/etc. Most parents have good interests for their children eventhough they do not go about in a correct manner. Hey, being the student that gets C's and gets parised for the one A can be more detrimental. My sister still thinks she isn't smart as me because she got average grades and praised for that one A. She is damned smart. Grades are not everything. It is your work ethic an how you apply yourself. No one gives a **** when you get out of school what grades you got. Same with your parents in a way, it may not be about ABC or D but rather the work ethic and application of what you know, and since you are in advances classes there is more pressure to go the extra mile. They want to prepare you for the real world, not in the sense of meaningless numbers but working hard for a goal and accomplishing tasks effectively. Just don't forget to have fun for awhile. Heck, why you are grounded from electronics, read a good book and go out with friends, to shows, concerts, etc rather than spending all life on the interweb
Good luck dude, You can get through it.