Learning self-love is a process that can take years.
As a young teen, I had never been in a relationship with someone before. This used to bug me a lot, and I would spend hours at a time trying to figure out what was wrong with me, or what was so undesirable about me that no one wanted to date me. At the time, I was very depressed and a lot of it had to do with my low self-esteem and self-image as a whole. I didn't like a lot of things about myself, including my facial features, my weight, my personality, and just, in general, the way that I came across to people.
I tried to change myself so I could fit in with the people around me, but I eventually gave up and said, "Screw it."
There was no way I could change the perceptions that other people had of me, and I didn't want to waste my time worrying about what others thought. Even though I was definitely still in a depressed and anxious slump, I forced myself to stop caring other people's opinions. Even if people had negative perceptions about me, there was nothing I really could do about, or should do about changing how they felt about me. And most of all, a lot of the negativity that I was observing was just me projecting my own insecurities onto other people.
Even though I've never been in a serious relationship, I have observed many people around me get into relationships where they latch onto their partners. So much of their self-esteem hinges on what their partner thinks about them, and while I think it's a great thing for your partner to make you feel good about yourself, I also think that you should have the strength and power to love yourself first. After that relationship is over, (which it likely will be) you will only be left with yourself. You have to be the source of love for yourself, because you should be the number one priority in your life.
I have seen so many people fall into a spiral of depression after losing a close friend or a relationship, and while this is definitely a normal and healthy thing to experience, I think having the power to love yourself will give you a different outlook when dealing with situations like that.
Self-love is a process, and I am still working on it. However, it is better late than never to start taking the steps to love yourself fully and truthfully.