Baby wakes up immediately when I set her down

My baby slept in the crib okay as a newborn, waking up every hour or two but that’s normal. At 9 weeks she started getting very fussy and would only sleep 20 minutes at a time and take two hours to get back to sleep. I was totally sleep deprived and started falling asleep no matter what I was doing during the day, so for safety of myself and my two children I started bringing her into my bed at night to sleep. She also only started napping if she slept on me. She’s 12 weeks old now and I would like to start getting her to sleep in her crib again because she has started scooting around and rolls to her side and I don’t want her rolling over on the bed or scooting up against me or off the bed. The problem is she wakes up before her back even touches the crib mattress. She absolutely will not fall asleep IN the crib I have tried putting her down drowsy and it won’t happen. I have no idea what to do now. I wanted to get started with naps in the crib but I can’t. She just wakes up. Please give some advice, and I don’t need to hear about the bedsharing decision. I had no other alternative and I get that it will make it harder for her to sleep on her own again. That’s not what I’m asking because I’m fully aware. Also she won’t take a pacifier.