Hi Psychedelic Fur,
I know the feeling, and after years of being alone - I finally found that love. Many of my friends have had multiple meaningless relationships, and in high school, they often had boyfriends or girlfriends just for the sake of it. I was never like that, and like you, I never wanted a relationship until I knew it was real and deep.
I had my first relationship when I had just turned 18 and finish high school. I am still with him, 2.5 years later, I am nearly 21 now. We have had a 4-day breakup and many ups and downs, but our relationship is very strong because of it and I literally could not see myself with anyone else (I could be blinded by love, who knows lol) but I believe we are soulmates, we read each other's minds, and have both stuck by each other through incredibly hard times in each other lives (some events people would never experience in a lifetime, let alone at 18-21). It's both of our first real loves, and who knows what will truly happen but all I know is that presently we are stronger than ever and are very happy together. I am very blessed, and I look at a lot of my friends and they tell me they have never felt that strong of a connection that I described before, even with one of my friends who had a close to 5-year relationship - she never felt that connection. So what we have is special, and every day I am grateful for that. I hope it does last a lifetime, but you never know what could happen, so I focus on the present and that we are happy together right now :)
My advice is to stop looking - this love will come when you least expect it, it may take a few relationships to get there, you're only young. But focus on yourself, and one day it will happen. For me, it happened when I least expected it. You could even have multiple love like what you describe. You only have the present, who knows what the future holds!
It will happen one day for you.