Communicate and Listen
Be honest about what you're feeling, seeing and experiencing, but do so gracefully, knowing that no matter how long you've been with this other person, you cannot know everything about them. Therefore, though you "see" her being lazy or "experience" his apathy toward you, it may be neither laziness nor apathy you're seeing or experiencing, but the onset of depression or an anxiety about your physical relationship.
Be patient with yourself and your partner as you learn to talk about things neither of you may have had to talk about before. Give yourself grace as you explain how you feel.
Listen just as gracefully.
Consider that every relationship requires compromise--even a relationship with an animal. Perhaps you feel you are compromising more than your partner.
Give concrete examples to help explain the cause of this feeling.
Suggest ways you could compromise more, and be willing to hear suggestions regarding your own ability to compromise
Allow for Change
Even adults change. Sometimes they change drastically: experiencing a car accident realigns priorities or a comment made by a colleague prompts a new hobby. Allow your partner to change, assuming the change is not harmful (though you may not understand it), and support them.
Realize that the longer you're together, the more each of you will change and that this is what can be most rewarding, not threatening.
If you feel your partner's change is moving them away from you, honestly communicate your concern without diminishing the possible importance of the change.
Look for the Main Issue
If a habit or tendency is driving you crazy (tearing off toenails instead of cutting them, leaving the curling iron on, wearing the lawn-mowing shoes in the house), think about what is really bothering you.
Ask yourself, "Is it the lack of respect that these small things indicate?" Why do you relate what type of shoes are worn inside to how much you're respected? Respected how? As a person? As the one who does all the vacuuming? As one who grew up in a house where shoes were never allowed to be worn inside, much less those worn for mowing the lawn? Do your best, perhaps with your partner's help, to determine what is really bothering you.
Then talk about ways to relieve that stress.
Realize You're Different
Notice differences in affection. How you show affection may not be the way your partner shows affection. When someone gives you a gift, even a candy bar she knows you like, her thoughtfulness communicates her affection. Maybe you feel affection when you're hugged or told how beautiful, handsome, clever, funny or talented you are. Maybe your partner feels your affection the most when you spend time together doing lots of things or even lots of nothing. Realize that we're all wired a bit differently in this area.
Be aware that how you receive affection is also the way you're going to attempt to show it ... and that your partner may not receive it that way.
Discuss these differences between you, then make an effort to buy gifts or give random hugs or do whatever your partner says communicates affection the most. It could save your relationship.
See a Therapist
Consider the fact that your relationship problems may be best dealt with by a professional. This does not mean you're hiring someone to tell your partner that you've always been right or to give you a five-step program guaranteed to fix all of your problems.
Working together, find a therapist who will listen objectively, challenge both of you and facilitate honest conversation.
See several therapists, if necessary, before you find one both of you are comfortable with seeing.
Know When It's Over
Consider that sometimes breakups shouldn't be prevented; sometimes breaking up is exactly what needs to happen.
Give this decision lots of thought.
Discuss it with your partner multiple times if necessary.