What is your opinion of yourself? Do you hold yourself in high regard or do you constantly berate yourself, talk to yourself in a negative way, with your thoughts? We show others how to treat us. If we are not good to ourselves, we are giving them permission to do the same, to view us not as a priority and to have less respect for us. Either consciously or most often unconsciously, they will treat you exactly how you treat yourself.
How much time do you even spend on yourself each day?
I was raised to always help others all the time and I was taught that to think of myself first was being selfish. No one wants or likes to be called selfish.
You do not have to do everything for everyone at your own expense. Superman and Wonder Women examples. And a relationship where we are last, is never a good relationship. We need to learn and understand that taking care of ourselves, physically and mentally is not selfish at all! It's just the opposite because when we take care of ourselves, we are the best version of ourselves and that best version of ourselves we then share with others. If you don't like yourself if you don't take care of yourself, how can you have healthy relationships? A relationship between two people is only as healthy as those two people are individually first. Give you respect and others will show you respect. Taking time for you doesn't take away from your other relationships, it actually enhances your relationships.
Homework: what do you like about yourself? Start a list of your attributes—the reason for doing this is twofold: #1—it makes you spend time on yourself and #2—it will get you to hopefully appreciate the person you are, and make the relationship you have with yourself better.
Remember: the most important relationship you have is the relationship you have with yourself. Begin to give yourself the same respect you give others, so you can become the best version of you, for you and everyone else in your life.