Your relationship with yourself is the first and most important relationship. Our relationship with others, especially romantic partners are our mirrors. What you can see in that person, is in you. What you see in them, means there is a level of that trait within you. This is why healing and doing the emotional work is so important. Your relationship with yourself is the most important relationship, you can only have a fulfilled relationship with someone if you are fulfilled within… You cannot expect or depend on someone to always adore you, love you, fulfill you and make you happy. If you are relying on someone else to do this then you are setting yourself up for failure. 
If you are saying or someone is saying to you ‘’you are my rock’’ ‘’you are my everything’’ FREE THEM. FREE THEMMM!! Free yourself from needing them, free them from needing you. 
Focus on your relationship with yourself, feeling fulfilled, feeling self love and forgiving yourself. If you heal the relationship and work on the relationship with your self, you will attract in someone vibrating on the same frequency as you. 
When you enter a relationship, come into the relationship without attachment, without an expectation of forever. Not everyone is our forever, sometimes people come in for a period of your life to teach you the lessons you needed at that time so you could grow and learn what you do needed to learn. If you enter a relationship with neediness or the yearning for it to last forever and needing this person to complete you, then most likely the person will feel it and pull away from you. The more someone relies on the other to feel happy, or thinks the other person completes them, then the other will feel this energy and most likely feel pressure and break away. 
If you are on the other side in the relationship and are feeling the pressure. Look within, where are you needy in your life? If you are feeling it from the other, then like I said earlier what we see in them is within us. What trauma or wound is there that has made you vibrate needy energy? You may have been abondended emotionally or physically. You may have been rejected. 

Dive into this wound and heal it, heal your relationship with yourself and learn not to depend on others to feel good. This may of been something you have already healed/in process of healing and you will see that this is why you attracted that partner in the beginning, because when you met them you were also vibrating this energy of neediness. You may have healed it by now and your partner hasn’t so now you are pulling away. Just continue focusing on your alignment with self, love for thy self and what focus on what YOU DO WANT. If you are focusing on what you DO WANT then it can’t not come! Whether the partner changes and grows, or you enter a new stage in your life alone. Always focus on thy self first