Reading your question already shows me that your desire is to do what is right even though it is not the easiest choice. I honour your heart and effort in taking a tangible step towards being free from these habits and addictions!
God made us people who yearn for intimacy, but true intimacy is meant to be fulfilled in Christ before anything else. When it comes to physical closeness, many misconstrue God as a rulebook keeper who just wants to deprive us of pleasure. That isn’t true. God is the one who created sex and made it a beautiful thing, but at the right time and person — that is, within the context of marriage.
Yet, in saying all these, we need to acknowledge that when a habit has formed, it is hard to break, and this is especially so for a sexual sin.
If your boyfriend also desires to break out of this addiction, it may help for both of you to seek a mature couple in church to process what has been happening and to figure out the best way forward. However, if he constantly pressures you to have sex and does not have a desire to be free of this addiction, it is wise (yet tough, I know!) to decide to break up. Being single will give you the space and time to understand why you are struggling with these issues and how to overcome them. While breaking up is a big decision that may help in the short term by stopping pre-marital sex, keep in mind that it is not a simple, clear-cut solution in the long term. There are often underlying root issues that you have to deal with even after breaking up.
When we engage in self-pleasure (like masturbation, binge eating, or even casual sex), often we are seeking to soothe and comfort parts of ourselves. These are legitimate needs, and could come from insecurities about who we are, fears of rejection, wounds from the past, or simply wanting to be loved. No matter how we try to soothe ourselves, however, it really won’t ever be enough. Would you consider bringing these needs, fears, and anxieties before God instead? Whatever it might be, God who created you knows and has the answers. In this way, you are choosing to open yourself to being comforted by God, instead of trying to soothe yourself.
With all this in mind, could you think of one wise person in your life with whom you feel safe and with whom you can openly share these struggles? This should be someone who will listen and pray with you, walk with you and point you to God’s truths. I truly believe there are many female leaders who would want to journey with you, not from a place of judgement but a place of deep love and desire to see you being restored in Christ.
Habits do not develop overnight, so, similarly, it takes time and perseverance to rid yourself of habits and addictions. I know this is a tough call and one that is painful, but I pray and believe that God is more than enough for you. He will give you the strength and joy to overcome and come forth victorious should you decide to walk in obedience and faithfulness to Him. You are not alone, dear sister. May Jesus be your ultimate treasure and the One your heart desires above all else.