HEELP!! re:19th old co- sleeping/feeding

Ok, so I suffer with bipolar disorder, which means sleep is ??ber important to my health, for that reason I found that having our baby on our bed from day one (allowing her to help herself to my asset) meant I didn't need to keep getting up during the night (lazy I know), but now baby is 19 weeks old she pretty much comfort sucks all night. If I manage to slip away from her she'll sleep about an hour before she realises and sobs until she is latched back on. I have tried comforting her in other ways to get her back to sleep but she's having none of it and will just cry. I can't let her cry it out (no way), but we have to crack this so I can then focus on getting her into her cot. I have also tried her with a dummy but she's not interested and screams. I know I have brought this on myself but I do also enjoy it as apart from this, she isn't a cuddly baby so this is how I get some snuggles in. Any ideas?? Maddie's Mom xx