I'm 18 yrs old and have temporal lobe epilepsy. is smoking marijuana bad for this?

Yes and no: In a strict sense, no, ingestion of marijuana actually raises the seizure threshold. However, more concerning are indirect effects: epilepsy can coexist with depression, which may be worsened by marijuana. Smoking anything can worsen lung function. Marijuana may induce some liver enzymes, which may speed up elimination of some antiepileptic drugs. Use your judgment in this instance. Good luck!