If you don't want to do cry it out, this happened to my daughter and what I did was sat in her room until she fell asleep (I did this until she got over the separation anxiety). She was also taking a really long time to fall asleep, but I just kept adjusting the bedtime (forward & back), and because I was sitting in there, I eventually figured out her perfect sleep time and just tried to get her in the crib 15 minutes before that so I wouldn't have to sit in there long. After about 3 weeks of me sitting in there, she started interacting with me while I was sitting in her chair and I would have to tell her that it was time to rest and that if she didn't settle down, I would need to go to the kitchen for 10 minutes until she settled. I would leave for about 10 minutes and although she was crying, she did learn to put her self back to sleep. After that, I just reassured her that I was right outside her door and that I was there making sure she was safe. I still always reassure her that I am right here and sometimes she does call me in just to check, but I usually only have to go in once to readjust a blanket.
I did try moving my chair closer to the door after about a week and tried sitting outside her door too, but for some reason, even that freaked her out because she wanted me where she could see me best, but you could try moving the chair until it’s eventually outside the room. I also had to go in a few times at night to repeat the sitting in the chair process, but I wouldn't pick her up or talk to her, just sushed her.
I also really had to reinforce her security item. She was already using baby Elmo as her security item, but I really stressed how he was there with her and I would make a big deal of putting him to bed and saying I love you to both of them. I also bought a few new books that talked about the security items that she still likes to read.
I also thought maybe she was sick or teething and took her to the doctor, but nothing was wrong with her, but it’s always a good idea to check. You may notice other separation issues with her now too – for me, my daughter only wanted me, had a hard time being left with anyone at daycare, and even my husband, and she also started climbing out of her crib to come looking for. I had to get a crib tent and had a hard time keeping sane, so I feel your pain!
Good luck tired mama!