Hi,
I can understand your distress regarding ejaculating much earlier than you desire. You seem to be suffering from
premature ejaculation. It is a condition when a male ejaculates earlier than desired which leads to dissatisfaction in sexual intercourse in either the person or his partner.
Since you have mentioned about
masturbation (handjob), I assume that you feel it is responsible for premature ejaculation. However, it is not true. It is important to understand that masturbation is a normal physiological process. Once a person becomes sexually mature, semen production starts which is a continuous process. A person the either has sex, or masturbates and has night falls. Masturbation doesn't lead to any physical, mental or sexual health problems. You can masturbate freely as much as you want without worrying.
It is recommended that you seek a psychiatric consultation. Treatment for premature ejaculation involves medications and behavior therapy. The best response occurs when both are used together. The outcome will be even more favorable if your sexual partner participates in the behavior therapy sessions.
Medications would include selective serotonin reuptake inhibitors like
paroxetine (daily) or
dapoxetine on as required basis. Behavior therapy sessions would incorporate relaxation training, sex education and learning methods like squeeze technique, start-stop method and distraction. The sessions can be done once weekly and 6-10 sessions can be required depending on your progress.
Hope this information was helpful. Best wishes.