Relationships aren't supposed to be selfish, while considering yourself it is important and only fair that you take a step back and also consider your partner - consider how you might be hurting your partner and things you might be doing to turn your partner off.
Living Outside What the Two of You Can Afford
It is important to live within what the two of you can afford. Once you've decided to be in a relationship with someone, you have to learn to respect what the person is earning per time and adjust your expenses to align with it. Avoid belittling and insulting your partner for the inability to meet your expenses, rather learn to love and appreciate while adjusting your expenses to align, or work hard, alongside your partner, to increase earnings to be able to accommodate these expenses.
In relationships, you should learn to choose your battles. Even if your partner is doing something wrong, it's not every wrong thing that you comment on, complain about or intend to change. Choose your battles. There are somethings you should just let go off completely or let go off in the mean-time to address later. You have to be wise about it. Negativity is draining and constant complaints are irritating, therefore it is important to learn to encourage, celebrate and appreciate your partner more.
Putting Everything Else First
Everyone likes to feel special and when in a relationship, it should be a priority to make your partner feel special as often and as much as you can. Your partner should always be your first priority. Even if you have to deal with something else before your partner, be courteous and let your partner know either before or after you've taken care of whatever it is. Remember, no one likes to feel unimportant, including you.
Forcing Your Partner to Conform To Your Ideals
Remember, your partner is not your doppelganger. As much as you two might have a lot in common, you can't have everything in common. Therefore, there are certain things you will allow your partner do or believe out of respect for who they are, to make them feel comfortable and to make them feel loved. It might not make you feel comfortable at all, but if it matters to them or they are unable to change it (no matter how hard they have tried), you don't force them, you learn to accept and accommodate them that way.
Be kind to your partner in your words, in your thoughts, in your actions and in your deeds. Be kind. Always ask yourself before you do or say something to your partner, 'Is this kind?', 'Can he or she bear this without falling apart?'. Kindness is simply the quality of being friendly, generous and considerate. Remember to be kind.