Finishing too soon

What do I do if my boyfriend cums like 30 seconds into having sex with me? It’s hard cause he apologizes for it every time and I say it’s ok because I don’t want him to feel bad but I don’t know what to do to make myself enjoy it more. Am I doing something wrong? There is probably only like 10 minutes of fore play before he goes for it. He asks what he could do better but I don’t know what to tell him. Should I just buy a vibrator?