Oil and water mixing

I 4fh1 isuzu elf 250 jus skimmed head cylinder worked well for the past 5 months but now oil and water mixing changed the head gaskett yesterday dint see any water gashing thru the rediator cap but this morning find it gushing again. And looks like the problem its on the head cylinder coz there is a leaking of both water and oil and now lm pissed off. Pliz help