I have a crush on a family member and i dont know what to do

My grandma had my mom and her two brothers in the 70s. Her husband (mom's father) died and grandma got married again. 20 years later she had two sons with her second husband. My mom's step brothers. Ever since i was a child i liked all my uncles, but i liked my youngest step uncle the most. He was always so playful with me, so nice, he is really handsome too. Both my step uncles are in their 30s now. Im 20. My youngest step uncle has a girlfriend, theyve been dating since they were like 18. We like each other a lot, she's like a dear friend to me. I feel bad that i like her boyfriend. I just can't help it. I liked him since forever. And im confused, i mean i think i dont want anything sexual, i just wish to be near him. Whenever he Is in the same room, i want to get his attention, be next to him or with him. He Is a physiotherapist and he gave me a massage when my back hurt. He put his hands on my waist, and told me to lean back on him. I loved that. When i was in hospital, grandma and him came to visit me, he hugged me and whispered in my ear that if ill ever need anything he will bring it to me. Ive never felt so good. I wish i could at least see him more often, we meet like twice a year. My feelings are tearing me apart. Its suffocating.