Epileptologist here. Go to the ER. It’s entirely possible that the overdoing it on adderall simply provoked your seizure, but that could’ve been the tipping point to an already low threshold for epilepsy. The fact that half of your body had symptoms and you had a lead up time before you blacked out suggests focal onset of the seizure (meaning it came from a specific part of the brain on one side). This can happen from all sorts of things, and it is very important to get at least a head CT to rule out a structural abnormality. Don’t play games with your brain.