I (M32) have a close friend (F31) I've known for about half a year. We spend tons of time together, text daily, call each other when we're stressed, will hang out and talk for hours, and often study together and then get food and drinks afterwards. The secret hanging over our friendship has been that I've had a huge crush on her since I met her, before we became friends.
A week ago, she broke up with her boyfriend and I've been comforting her as she processes it. Today, I was studying together and we ended up talking about our respective experiences with heartbreak and how messed up it makes you. She then started talking about how she doesn't want to start dating again but she thinks it's important that she puts herself out there. She told me that a friend of hers suggested she try blind dates. And asked me what I think. My idiot brain could think of no response other than brutal inappropriate honesty and said "I think you should date me instead."
She was clearly shocked by this, and after saying she felt very uncomfortable, told me that she'd rather just be friends. We kept studying together, I was going to leave but she told me to stay. And it one point she asked me to watch her stuff as she goes to the washroom and when she came back she was clearly crying. We parted on apparently friendly terms but I feel terrible and guilty, not for what I said but for when and how I said it.
TLDR; I told my close friend a week after her breakup that I want to date her and caused her to cry.