A very tough time for you and your husband, especially with a toddler too! Can I ask if your baby is clingy when awake? My 9 month old has always been clingy from day 1. I had this image of me having visitors in the first couple of weeks after having my baby and us all cooing over her whilst she lay swaddled in a blanket and drifting in and out of sleep.
This was not the reality and she barnacled herself to me for a good few months! She was never calm and content on anything but a person and I had no choice but to carry her on me or she would just scream if put down, only sleeping when close. It is so hard, particularly when you have a bad back. I expected her to cry but not everytime I put her down and not for hours on end in the evening.
At night I slept with her on my chest for 2 months, again very hard as you get no personal space and after carrying them for 9 months this is a desperate need! For 2 more months she slept between me and my husband. There are lots of people who will tell you this is wrong but I doubt these people have ever been in a situation where there is no other choice! To be the best parent you can be you need to sleep. Research suggests children who co sleep with parents have been found to grow up feeling more secure. Some people will tell you the baby/child will be stuck there forever but for us this was not the case.
At 4 months there was a turning point and my daughter could be put in her Moses basket asleep or sleepy and not scream. From 4 months she slept in a cot in her own room. It took 6 months and weaning for her to sleep longer stints at night but this is common. Gradually she began to comfort herself with a bunny blanket and at about 7 months she used it to help her fall asleep. Although during the day I rock her to sleep with music as she cries if put in cot.
I do think my baby had colic and she was found to have a tongue tie, at 9 weeks old, which made it difficult for her to feed but I truly believe it is just her personality and what she needed. At 9 months my baby sleeps through most nights and my husband and I have our bed back (she is even missed by me sometimes
I was told by someone to hold her close, let her sleep on me if needed and she would feel secure enough one day to sleep independently. For me this was true and looking back I am so glad I gave her what she needed. She is still a clingy baby with a dislike for car seats and buggies. She is strong minded and definately not laid back. She is gorgeous though, very cuddly, active and very able.
Some people find controlled crying helps, if that is a route you want to take but I don't think it works for all babies and 6 months is the suggested minimum age. I know it is hard now but it will get easier. I just got through it by telling myself it would not last and it definately didn't
good luck!