the one that got away

my boyfriend and I didn't date for long (only 8 months) but he was my best friend. I'd never felt so close and comfortable with anyone before since I'm the type of person that doesn't open up to other easily. within the last few weeks of our relationship he said he had been feeling off. I tried to help and be there for him as much as I could but eventually decided that sometimes you just have to let go. I'm still in love with him and am incredibly sad that it's over. please help how do I get over him?