I can relate to what you are saying to a point. My dh and I were married and were both virgins when we married, but struggled with purity issues as well. We too, were in the confessional a lot. I wanted to break up because of it for he was to help me to heaven and his actions were bring me down with him. I too had a priest tell me to break it off. It was not easy, but we struggled with the purity issues and I resented my dh for leading me down the path of sin for I was completely pure when he met me. I know I am at fault also and boy it bothered me for years, even after we married.
We did marry and have been married for 8 years now. It has not been easy and the same problem of being patient and respecting me are still issues in the marriage, but we had other issues as well that had nothing to do with purity. We made it and continue to work on our marriage daily. We still have problems, but what marriage is perfect?
I can understand what the priest is saying. If you are confessing the same sin over and over again, he is just trying to help you see that it is habitual, as you acknowledge, and a problem. If you and your girlfriend can’t seem to be pure and chaste, then yes I agree with the priest and you should probably break it off. You know that part of the Bible where it says if something causes you to sin, better to cut it off than suffer the fires of Gehenna or hell. I use to think of this verse so much while dating my dh and did break it off three times. He finally knew that I wanted to be chaste and pure and he tried all the harder. It worked out. Now, I am sure that I am and was much older than you are now. I was 32 years old when I met my dh and started to date. I wanted to be a nun and he was studying to be a priest, but never made it, obviously.
Please, if you decide that you and your girlfriend can continue to have a relationship and be chaste, just don’t put yourself in situations that can lead to the sin. Don’t be alone in any place except in a public area. If kissing leads to the sin, than only have short kisses. Basically, do anything to help each other out and see if it can be done. We are all human and we do sin and thank God that He is a loving and forgiving God. Don’t give up hope and most of all avail yourself to all the Sacraments that our great Church has to offer. I know with us, receiving Jesus in the Eucharist daily helped us stay pure of heart. We didn’t want a day to go by where we could not receive because of mortal sin. I am happy to hear that you have a spiritual director and that is so great and a blessing. I wish I could get one, but they are not very orthodox here and they would hinder my spiritual growth. Listen to your priest and just discern everything he tells you to see what the Lord is calling you to and your girlfriend.
I hope this helped you. I will keep you in prayer. One more bit of advice if I could, please read and reflect on the Bible if you are not already doing so. I know this was an area that my husband still struggles with. We need to meditate on the Bible and see what the Lord is telling us through his word and what is happening in our life.
You are off to a good beginning and that is the DESIRE to be holy, chaste and pure. God bless you for that. Be patient with yourself too.