I have this foul odor and small blisters on my penis what is the percentage that it could be herpes?

Very high. Blisters are very likely herpes. Foul odor may come from bacterial infection from broken down herpes skin lesion.
Likely. Genital herpes causes blisters on the penis caused by a virus. It generally causes some discomfort but not severe pain. It is not common for it to cause a foul odor unless perhaps it is infected (from sexual intercourse, scratching the lesions, etc). If there is persistent fould odor or worsening of the blisters, they need to be evaluated.