Is it possible to use your security deposit to terminate your lease early on an apartment?

I have moved into a duplex in Eugene, OR and we have cockroaches. Now I want to move back to Medford and get out of here, but we're leasing this apartment until March. My landlord has our $600 security deposit and that is how much it costs to terminate the lease. I am also wondering if the cockroaches are reason enough to leave. No we haven't had an exterminator come in yet and spray, but I don't think that is a safe alternative, as I have a 16month old son who would be exposed to the toxic chemicals. I don't think there is a 100% safe way to bug bomb your house.... What are my rights here? Do I even have a case?