Is there a natural cure for early ejaculation?

Yes. If by natural you mean herbal or other non-western medicine supplements/meds- there isn't anything that's been proven (despite what you may hear) if by natural you mean non-pharmacologic: i recommend start-stop technique (stop as you are getting close) as well as the "squeeze" technique (you or partner squeeze the glans when you are getting close) both are quite effective behavioural methods.
Another simple trick. Try having your male partner masturbate to orgasm before you have sex. Assuming that does not interfere with him getting an erection, that may delay his orgasm enough to solve the problem. A sex therapist can give you a lot of things to try that help a lot.