Am I likely to grown out of a peanut allergy? Is it worth getting retested?

Unlikely to outgrow. People usually do not outgrow peanut allergy, so one can get his blood tested or his skin tested, and then see the allergist to perhaps eat a peanut butter cookie at the allergist's office, and stay there for a while to watch for any reactions. Anaphylaxis can occur with peanut allergy, so patients usually carry an epi-pen self-injector for emergencies.
Children maybe. Current data suggest that about 20% of children may "outgrow" peanut allergy. Most of these are younger children with milder reactions. A person who has had a severe, anaphylactic reaction, who has a very large skin test or very high ige blood test to peanut is unlikely to outgrow their peanut allergy. Adults are less likely to outgrow peanut allergy.