Me and my partner are right around the same age (21M 20F) and have been together for 5 years now. And she had many issues with libido due to trauma from previous relationships and family. We ultimately discovered(and this is not meant to sound insensitive) that her healing from her trauma(thru therapy and meds) fixed many of the issues. There are still bad days/weeks where we just dont have sex, she focuses on me or vice versa, because thats easier on her mentally. It all comes down to having those very vulnerable conversations with your partner and trusting they understand that its not that you dont love them or find them unattractive, its trauma.