From your description, it does look like you may have PE (premture ejaculation). You need to know that by international agreement, premature ejaculation
is ejaculating either before penetration or under 2 minutes after penetration during sexual intercourse. Also, this should happen at least 50% of the times. Please understand that it is one of the most common sexual dysfunction
with around 40% men suffering from it at least once in their life time. If this problem has persisted since the beginning of sexual activity (always been there), it is called as a 'primary' problem.
I suggest that you see a doctor who specializes in sexual medicine and seek some treatment. In my clinical experience and practise, I tend to get better results from involving the partners in the treatment programme.
Good luck !