AITAH for distancing myself from one of my best friends because they confessed their love…

I (20F) and one of my best friends (20M) worked together and got pretty close during that time. We would hang out all the time, call and text a lot, he even came over for holidays. He was an amazing friend to have and I miss him a lot. For backstory, I am in a serious relationship with my boyfriend (20M) who I have been with for almost two years. He is amazing and has always been there for me even before we were dating. I talk about him all the time and he is such a big part of my life. Back to the best friend thing, I recently got a promotion and was moved to a new location. After about a week at my new location, my best friend asked to call me on my way home from work. This was fairly common for us so I didn’t think anything of it. When I called he expressed that he has had a crush on me for a few months and realized how much it has affected him with me being away. I told him that I still love him as my friend but I do not feel the same way. I expressed that it upset me because I’ve talked to him about how every time I have a guy friend it turns in to them having a crush on me, and now it happened with him too. I know it’s not his fault and he can’t help his feelings, I’m not mad I just don’t really know what to do. I told my boyfriend and he was clearly uncomfortable because of how much we hung out, but wasn’t upset with me or him. I distanced myself a lot from him for the past few weeks because I felt like I needed some time and space. My friend is very clearly upset with me but I’m not sure what other options I have. I feel like we need space from each other because I can’t hang out with him like I used to knowing that he has a crush on me because it makes me slightly uncomfortable and I feel like it’s disrespectful to my boyfriend. Am I the ass hole? Does anyone have some advice? I feel guilty for distancing myself but I know it’s right for me, but what about him? I care about him a lot, I just don’t feel the same way he does.

Sorry I know this is a long post. Thank you :)