My close friend likes me and my boyfriend hates it

I've had this friend for about 7 months already and me and her are really close. She's very sweet and understanding and we go to school together. I found about 4 months ago that she really liked me. She knew I had a boyfriend and she respected that. I've been through a lot these past couple months. From constantly being in the hospital for passing out & going to a mental institution for a couple days. She was there through all of it talking with me on the phone when my own mother wouldn't answer my calls. We have a lot in common as well. Since we both have had depression and anxiety issues. We have very similar problems involving our parents. We've grown very close over the few months I've known her and I see her as a very good friend & nothing more. I don't like her like that & I love my boyfriend very much and he's very angry about the fact that I hung out with her yesterday. We've been arguing all day. He says why would I hang out with someone who I likes me. I told him that I don't understand what's wrong if I'm not cheating, she's only my friend. I love him very much and hate seeing him upset but I don't want to lose one of the only friends I have. Please lmk what I should do. And comment what you guys think about having your s/o hang out and be friends with someone who likes them.