4 month sleep regression

My little one turned 4 months old at the start of the month, and had her two bottom teeth come through. From 2 months old she slept through the night (very lucky I know) but ever since her teeth have come through and the sleep regression has hit, she has struggled to resettle to sleep in the night. This varies from 130-530. Some days I spend 1.5 hours settling her and putting her back in her bed, and her waking up as soon as she goes down, or she gets irritable and groans and rubs her head on the mattress and pushes her dummy back out. If I bring her into bed with me, she’s out like a light and will sleep until morning. I really hate co sleeping, I find it uncomfortable, and I’m so scared that I barely sleep anyway. Has anyone got any tips on how I can get her to settle in her bed any easier? I’ve tried an extra layer, so I don’t think she’s cold, she’s not hungry, as she’s not crying, and not fully awake. I know I had it easy when she was smaller, but I’m really struggling now she’s up so much! Any help would be appreciated ❤️