Great advice! A small bit of extra advice from my own relationship is focusing on talking about how things make you or her feel. And remember in this that feelings are never wrong, but can be misguided by (IE) not knowing the full picture. (Though never just assume thats the case for someone else)
Your feelings are valid OP! But, hers are as well. Try figuring out what’s making you both feel unhappy about your relationship/sex life.