Sleep deprived - baby barely sleeps

Hiya!

I have a 14.5 week old baby, and as of the last 2-3 weeks, this baby basically only ever sleeps for an hour. Whenever she then wakes up, her eyes are closed and he mouth is wide open, head tossing frantically from side to side, making sucking noises, so I feed her; and I feed her for like 20-45mins, put her back in the crib and then either she wakes up, or she sleeps again for an hour; this is even at night. I’m so exhausted and I miss cuddling my OH when sleeping too, but she simply isn’t sleeping longer than an hour. I’ve tried keeping her in my bed, but the moment I’ve fed her and leave, within 5mins she cries and wakes up.

Before this problem arose, I had her in a sleeping bag (because it was wintery, and she didn’t like being swaddled. She started getting hot in the sleeping bag, as it was a high fog one, so I TRIED swaddling, but with one arm out, and I used to get 3-5hrs with both these methods. Now none are working. I even got a Love To Dream summer transition swaddle. She does not like having her arms trapped or one trapped, nor having her legs kinda trapped. I was going to buy the nestedbean, but saw better reviews for the LoveToDream and thought I’d see how this was before buying the NB, as it’s £100+ to buy, with mixed reviews.

Whenever I’ve fed her on the bed and lift her to take her to the crib, I spend 15-20mins trying to making fall back asleep, as she comes out of that deep sleep and into a shallow one so fidgets and groans a lot.

Pleeeeease can someone help?!?