Lola, I am sorry, but there is a huge difference between a person preforming a job and someone getting revenge. Until you open your eyes and take full responsibility for your own actions and deal with the emotions and negative thoughts, you are going to continue to dig a deeper hole for yourself.
This isn't to make you feel bad about yourself, but to get you to see the damage you are doing to yourself. He paid a person to provide a service. He did not go out to bars or where ever and pick women up. He went to an establishment that sounds like it cares about health and they only touched him with their hands. Less likely of transmitting diseases. You went out and found men to use as weapons against your boyfriend. You have no idea where these men have been and what their health is like.
What you have done may be 'less intimate' to you because the males didn't take their clothes off, but you put your mouth on a man's penis with the intention of getting him off and then kissed your boyfriend with that same mouth. Be honest with yourself about what you have been doing and walk away from this relationship before you are going farther with other body parts that you deem 'less intimate' than a hand-job from a professional.
You are 18 and can choose whether you want to continue down the path you have taken or to choose a new path where you are not acting like a masturbatory aid. You have to be willing to give yourself support before anyone else can. That means giving yourself permission to walk away from a toxic relationship and starting over.