Parents come and go. Children come and go. Partners can come and go as well. The only person who will ALWAYS be with you is yourself. If you're lucky a special friend or two. But for the most part, the people who surround you are like the seasons -- they stay for a while, and then they're gone, for whatever reason -- it isn't usually because they dislike you, but because life sends us on our separate journeys.
I'm visualizing a rock in a stream. The water molecules each pass the rock, and caress it, but then they leave. There are always water molecules, but they are never the same. Some are nearer and some are farther, some pass by quickly, and some eddy around the rock for a time. But at some point, they always leave.
So loving ourselves is what we have to do first, even though it may be harder for us than for people who haven't had our struggles. Once we love ourselves fully, then we can truly commit to loving other people, and give them the love they deserve for the time they spend in our lives. Always aware that nothing is eternal, and always aware that we can love powerfully in THIS moment, and then forever, even if we never meet again.