There is no doubt that practicing oral sex outside marriage is prohibited and a grave sin, you have to give up this sin, regret what has happened and be determined never to go back to it. Do more good deeds to expiate and cancel out your bad deeds, do those things that will help you to remain chaste, and hasten to marry according to Islam.

It is not permitted at all for a man to shake hands with a non-Mahram woman.