Should refrain from categorical peremptory tone of snide remarks and accusations. Especially not reject "a threshold" criticism, which you can hear in his address. It is better to try to think: what caused it? Maybe you really did not behave in the best way?
Try to treat more severely to yourself and to your loved indulgent. Do not try to alter it, breaking character. If you love a person, you have to take it for what it is. Of course, all people have flaws, and some habits, behaviors can really strain your partner. But you can not make fun of them, but even more so, to require rejection of them in a harsh, categorical form. You can always negotiate, to find some mutually acceptable compromise if behave sensibly and tactfully. Do not impose their tastes, opinions, even if they seem to you the most correct. After all, as the proverb says, "The taste and color of comrades not."
Often remind yourself that this is what the person you loved, came to the conclusion that he is the best. Yes, the same ardor anymore. Your relationship, quite naturally, became more restrained. But do those same qualities for which you once loved partner disappeared? If desired, you again make out them without difficulty.
Do not skimp on the good words on the signs of attention. Praise partner (because surely there is for that). Try to keep you came warm, welcoming aura. And the results were not long in coming - your relationship will improve.