Criticizing one another will only lead to further unhappiness. Love and accept each other as you are and your relationship will magically transform.
If you do not love your partner enough to accept them as they are then it is time to think about moving on. We can not change anyone if you entered into a relationship with the belief that you can change the person you are in for a rude awakening. Permanent change only occurs if the person desires to change. Insisting that someone changes to remain in a relationship makes for a very tense situation and if they do not genuinely wish to change it can add trust issues to an already unpleasant situation.