Is it possible to get S.T.I.s from recieving oral sex on the penis?

Yes, there are numerous STDs and STIs you can get from oral sex. Although you seem to think that you can't get herpes from oral sex, you can. Hsv-1 can be spread to the genitals and it does not become hsv-2, it is still hsv-1 on your genitals. You can also get HIV, HPV, chlamydia, gonorrhea, syphilis, and hepatitis from oral sex.