I (27M) can’t stop obsessing over my former coworker/good friend (40F)

TLDR: I can’t stop thinking about my friend/checking their social media. Im confused about my feelings, and wondering if I’m overly-obsessed, in love, or just extremely anxious that the friendship will end.

I just left my job this week, and was pretty torn up about it because I was going to leave my coworker behind. She is an amazing friend, and it felt like we formed a strong emotional bond in a short time. We were both upset about me leaving. We even both told each other we love each other (in a platonic way, but this is definitely not something I have ever told a friend before.)

Since leaving (Wednesday was my first day gone) I feel like I can’t get her off my mind. I check her social media all the time. We have still been texting everyday, but I’m so worried that we won’t stay in touch over time and will grow apart. Moreover, I have a confused feeling that I might have fallen for her, and I am definitely sexually attracted to her. However, she has kids and a husband. I wouldn’t even consider doing something to mess with that, and am perfectly content to stay friends.

I guess my overarching question is: why am I so obsessed? How do I navigate these feelings? And how do I make sure we stay in touch? Any thoughts would be appreciated.