I am now so desperate I'm not sure what to do. I have the most unhappy non-sleeping baby. Sometimes I think it's improving and then it all turns to crap again.

I am the worst mum to my older daughter because I just so tired.
DD2 is 4.5 months old and is just miserable. I'm not even sure where to start. She is a worse sleeper now than she was a month ago, there is just no improvement. I posted a while ago thinking I had cracked it... More fool me.
She is exclusively breastfed, she feeds well and is gaining weight well too. I have suspicions that she may have some digestive problems and I am currently waiting for a paediatrician referral and have posted on the allergy board with symptoms and have excluded dairy from my diet in case this is the issue.
So the sleeping... She is a 45 min napper, I have tried W2S that worked a couple of times but not recently, tried shh pat that worked a month or so ago but not now, she gets too stimulated now and when it was worked we were doing it for a couple of hours every night. I feel that PU/PD will also be overstimulating she is so sensitive. She did (until 5 or so weeks ago) sleep 7pm until DF at 11.30 and then woke a couple of times after this for feeding during the night. She is now waking 10 or more times between 7pm and DF. She wakes crying or screaming, she never wakes happy, either from a nap or NW. She hardly ever smiles and has never laughed

I have tried White noise with the radio on static and thought this worked as the 3rd time I used it she napped for 3 hours (first time ever) but it has not helped since.
She is still fully swaddled and i think she still needs to be as she is still very jerky, probably from being OT all the time. My day and night is constantly filled with thoughts about how I can get her to sleep, working out how much sleep she's (not) had and stressing about the night to come. She has a paci that I know has now become a prop but i daren't get rid yet. She is put to bed awake and will sometimes go to sleep independently but will not stay asleep.
This was our EASY today
E. 7.30
S. 9.00 (tried for 15 minutes to return to sleep)
A. 10.00
E. 11.00 (usually 11.30)
S. 12.15
A. 1.00
E. 2.30 (usually 3.30pm but moved earlier in the hope that she would be hungry at last feed
before bed feed better)
S. 2.45
A. 3.00
S. 4.45
A. 5.15 (bath at 6.00)
E. 6.30
S. 7.00
So far tonight she has woken about 5 times and she wakes screaming (it's only 10pm). We are patting her gently to calm her in her cot until she settles, and then a few minutes she is screaming again (with us still in the room).
Our EASY just cannot work because of the short naps. Until today I had keep the E to 7.30, 11.30, 4.00, 6.30 but read something today about moving afternoon feed to earlier to ensure an effective last feed.
I am hoping someone can help before i leave her to cry.....