I started dating my current boyfriend without breaking up with my ex.
That sounds awful. Why did you not break up before you started dating?
My current boyfriend pressured me into it. Also I was emotionally unstable then.
You should have broken it off before dating your current boyfriend. Dating two people at once without the consent of both people is unacceptable.
But I don't want to end it with neither. I think I'm going to date them both.
That is not a good idea. You need to be honest with them at least and make sure that both of them know that you are dating them at the same time. Otherwise you might end up with no boyfriend at all.