Is it normal to suffer from delayed ejaculation?

Dear internets,

I am a male college student who happens to suffer from delayed ejaculation; meaning that during sexual intercourse and foreplay, I am unable to ejaculate exclusively from my partner's actions and often have to masturbate to the point of orgasm and be "finished" off by my partner. This usually isn't a problem for me, but generally my partner is frustrated by their inability to "please" me, which in turns makes me feel guilty and thus makes me want to try harder, which never seems to do the trick. Whenever I masturbate alone, I seem to be able to attain an orgasm rather quickly, but when with a partner, it just doesn't work.

I thought the problem was that I masturbate too frequently, but I would sometimes go a week without masturbation and the problem would subsist. If this information helps, I have had two sexual partners and have only had sex with each a handful of times. I am often very bad at handling stress and suspect that I suffer from a form of anxiety/depression.

I have met others with this problem, but they did not have an answer and I still do not know if it is normal. Either way, I would gladly hear some of your advice on this topic.

Thanks,
K