The only reason to rejoin the Church would be because you are a Christian who knows that Jesus Christ founded the Catholic Church and are therefore compelled in conscience to join the Church and follow all that it teaches, which includes marrying according to Catholic marital law and promising to raise any children you are given as Catholics.
Although, with the proper dispensations from your diocesan bishop, it is possible for a Catholic to marry a non-Catholic in a non-Catholic ritual, interfaith marriage is a very difficult prospect that I cannot recommend to anyone. The primary ends of marriage are the sanctification of the spouses and the rearing of children for the kingdom of heaven.
As a Catholic you would be obliged to promise to raise your children Catholic, while your potential husband would understandably feel that he could not raise children in a religion he does not himself believe. When spouses disagree on the religious basis for fulfilling the ends of mutual sanctification and rearing children, they are going to face grave difficulties. Some interfaith marriages work and those who make them work are to be congratulated, but all too often spouses in interfaith marriages see their own faith suffer and see their children so confused by religious dissension in the household that they lose whatever religious faith the parents were able to instill.
I recommend working on resolving your own difficulties with Catholicism. If you are able to resolve those difficulties and can in conscience rejoin the Church, your first obligation to God is to do so, whatever the understandably regrettable consequences that might entail for your current relationship. A relationship with another person is not sufficient excuse to refuse to follow your conscience into the Church if you are given the grace to understand that you must again become Catholic. You would then need to be honest with your friend about your obligations to practice your Catholic faith and promise to raise children Catholic. The relationship may not survive, but if so, both of you would then be free to marry spouses who could best help you and future children make the journey to heaven. God bless.