I have a bb sized bump in my urethra it seems. goes away when its erect and since i noticed it, i ejaculate almost the second i start having sex. ?

See a doctor: A "bump" inside the penis is suspicious for a genital wart, but there are other possibilities. Maybe it's still there when erect, just hard to feel through erectile tissue. In any case, this should be professionally evaluated, preferably by a urologist. The premature ejaculation is an entirely separate problem and may be mostly psychological. But you could also discuss with a urologist or your GP.