My penius is small and weak?

Evaluation? The size of the penis, unless it is micropenis, is not correctable or changeable. For erectile dysfunction, several medications are available via prescription, as well as vacuum erection devices, or penile prostheses, depending on the cause and severity of the problem. You need to see your physician and likely a urologist for further evaluation.
Penis. Size and poor erectile function in general needs evaluated. Please see a physician. Urologist preferably.