Hello!
There are a variety of resources for young Catholics struggling in this area! First and foremost, I think it would be most fruitful to spend some more time in prayer (perhaps a Hail Mary and reading and meditation on Scripture) and reflection on the purity and Christ’s love, which was a willingness to suffer for his beloved, all the way to the cross.
As a basic precaution, avoid being alone together. This is important enough for all Catholic couples, but you may need to be extra cautious, because your body chemistry is such that now it will feel even more natural to be close, touch, etc.
Remember that the real you is the saint you will be if you follow God’s call. The real you is never the sins you habituate yourself to.
Frequent the sacrament of reconciliation, and attend Mass more often if possible.
I personally love Mother Theresa a lot. She is very simple and real, and she probably lived with more integrity than anybody I will ever encounter in my life, and all of her life was about Jesus. Try reading No Greater Love, preferably if you can find it at a library, but it is worth the cost to buy as well.
‘Purity saints’ (all of them are!): Our Lady,
St. Maria Goretti
,
St. Therese de Lisieux, St. Augustine, St. Padre Pio…
pureloveclub.com/ has some good discussions, articles, and FAQs about purity.
This is a list of websites for battling impurity submitted by posters.
Good luck! Above all, remember that saints are people who picked themselves back up after sinning!
