My girlfriend and I have been together for 2 years and we live together. Since October, I've noticed a change in her behavior. Not the type that would make me think that she is unfaithful no, but the fact that she is more and more depressive. She is like, NEVER happy, she never smiles, she takes all I say as a reproach, she gets mad for every little things, and moreover, she is not loving anymore (attentions, cuddles, words, sex, etc). I thought it was something brief, but it took too long to be normal. I think I've tried everything, first I tried to talk to her but she is a wall, only responding me that it's not serious. I tried taking her to her favorite restaurant to make her feel pretty and desired, making her the gift she always wanted, taking her in UK for a trip, I cook her the meals she likes (I'm the one who is in charge of the kitchen), everything. What do you think would work to make her smile again?