hi there
sounds very familiar to me. No idea if it's helpful to read about a similar story, but also perhaps you have some insight for me. My lo is 9 months and we did sleep training 2 months ago. it went fairly well although pretty awful for me, and after about 10 days ( it got better each day apart form day 3 & 4) he went from being breast fed on demand and up to 4 or 5 times on a bad night to 0 times. and slept through until about 6.30am. We had c. 6 really quite good weeks....
However, recently we had a fright when he came down with a high fever, blotchiness and cold hands and feet and drowsiness ( 2 weeks ago) so spent a day at the A&E ( emergency room) to check for meningitis. Luckilly it wasn't but some other non specific virus.
As a result I let the whole sleep training thing slip ( when he had the very high fever I was breastfeeding on demand) He is now teething ( incisors), and clearly in pain at some points during the day. He cries out, out of the blue and is gnawing his hand like a dog on a bone, and is waking 2 or 3 times a night with similar reaction to the ones you describe. Livid screaming, not happy in my arms in any position for long, nor lying down, and does some odd jerky thing with his body and stiffens his legs. I give him baby paracetamol but the only thing that gets him back off to sleep quickly is a breast feed, although he cries when he is finished for c. 1 min. before dropping off. ( he used to fall asleep quietly afterwards).
I cant work out if it's a "I want my breast feeding at night back", willful thing or an allergy or some other thing. I have a feeling he may be intolerant to some foods including mango and or tomatoes as I think it is at least the the 2nd time I noticed he sicked up after dinner. Hard to tell really. He did have reflux although this seems much better and has a tongue tie that they wouldn't operate on, no idea if any of this is relevant.
Either way my instinct is it is a combination of short term painful teething and some kind of chronic digestive issue. (he seems quite windy, mostly farty) so I have a suspicion he may be slightly lactose intolerant, or maybe I am eating too much sugar (have been a chocoholic since pregnancy) and passing it on to him.
On the whole he naps well, a spin off of the sleep training that has worked out well and can put himself to sleep sometimes crying and occasionally without a peep, but this night time thing is tough. Feels like we are heading back to square 1. Hope not.
Any insight or suggestions much appreciated.