It's been 5 years but I still like my childhood friend

I'm 20 now. I live together with my boyfriend for 2 years now, and we've been in a relationship for 3 years. It's been 5 years since me and my childhood friend talked... but just these few days, I woke up thinking about him with a heavy feeling in my chest. In my childhood, he was the only guy I ever had crush with. It's pretty unusual but he was the only one I ever liked back then... no celebrity or anybody, just him. But he's 6 years older than me so he only sees me as a "younger sister". Worse, when I was 12 he had to move to Japan. We talked every weekend for hours and hours because he was too busy with school in weekdays. Then, he fell into a deep depression... since then he avoided talking to people online, and somehow in real life too. We never talked afterwards. He deleted his Facebook and Skype account. I waited for him for years... I turned down every single guy, and every birthday I had I would check my e-mail every now and then to see if he would send me a greeting. Nothing happened. My friends said I was weird for never dating anybody when I was teen and just waiting for a guy thousands of miles away. I focused on my studies thou. But last year, for the very first time after 5 years he messaged me. He said he was in progress of becoming okay now... I wanted to be in touch with him but still now he hasn't replied. I love my boyfriend so much but.. I don't know. I don't know if this is a romantic feeling or only a love for a "big brother"... but I feel so upset because he doesn't let me in... he keeps everything to himself. I know I'm not special enough for to him open up to me. I always wish I was something more. I always do.