I know these meds can make your body feel miserable at first, but try to give yourself some time to adjust. A 7.5 mg dose of citalopram isn't likely to be enough to help with depression. If you find the increases bothersome, ask your pdoc if you can titrate a little more slowly. That might make the periodic increases less bothersome.
And no, 10 mg isn't an overdose. You're feeling temporary side-effects. Hang in there.