I totally agree with everyone else here. All their suggestions are great!
I too was on bedrest, although for only 6 weeks. My son was about the same age as your daughter is now. I totally felt like I wasn't being a Mom, that I was neglecting my son, that I would never regain my bond with him, etc. Pretty much like how you feel.
Up until I was put on bedrest, I pretty much did everything for my son. DH definitely helped, but I was definitely the one that my son would come to when he didn't feel good or got hurt. That did change when I got put on bedrest.
Although my relationship with my son changed over this short time period, I'd all in all it was for the best. My son learned that he could depend on his Dad to take care of him and he became more independent and confident in himself (not that he wasn't already independent enough already :)). His relationship with my hubby definitely blossomed over the 6 weeks of bedrest, plus the additional 8 weeks of recovery (I ended up having a c-section, then had an emergency bowel obstruction surgery 1 week after the c-section). So this transition from me to DH was good. I was able to heal and recover and spend time concentrating on my daughter and knew that my hubby could take care of my son and that everyone was happy and comfortable.
It was also a boost to my hubby that he could actually take care of my son. Bathe him, feed him, take him to the park, take him out on errands, all by himself. Before this he was always a little hesitant to bathe him or to take him outside of the house on his own. He was always afraid he do something stupid like lose him or some huge accident would happen.
I also agree that you should still be included in the everyday activities of your daughter. When I was on bedrest at home, I would be sure to hang out on the living room couch when my son was up. Then when he napped or went to sleep, I headed back to my room. I let everyone else do all the hard stuff (cleaning, errands,cooking,etc.) My job was to "bake a baby", play with my son on the couch so the others could get chores done, cuddle him, praise him while he ran around the living room playing, take pictures and video of him and tell the others in the house what needed to be done and when.
The hardest part was having to be on bedrest in the hospital for the last 4 weeks of my pregnancy and then being in the hospital again for a total of 2 weeks after delivery (4 days for the c-section, then another 4 days after my bowel obstruction surgery). Someone always brought my son to see me in the morning before preschool and in the afternoon just before dinner. He was so frightened of seeing me in the hospital room that he wouldn't even come and sit on my lap. All the machines and beeping and lights scared him. That just broke my heart.
After my daughter and I came home (she also had to go back to the NICU the day after my bowel obstruction surgery because her bilirubin levels skyrocketed) it took my son a good week or so to really be comfortable around me again. I think he was just afraid to let his guard down, because so many times in that last 2-3 months I would be home for a few days, then would have to spend a few days in the hospital for preterm labor, then I'd be home a few days then have to go back. Then I came home with a baby only for both of us to return to the hospital again.
But once he figured out that Mommy and baby sister were home to stay, things got better fast. For about 2 months every morning he'd run into my room just to make sure that I was there....gosh I am starting to tear up just thinking about that horrible time and how scarey it must have been for him and it's been 2.5 years since then.
My point to this horrible and long story is that, in the end, your daughter will be fine. She will still love you. Just right now, she has to learn to depend on others until you can get back on your feet. It's a good thing for her to become a little more independent right now. She will have to be able to have confidence in herself and be able to trust others to care for her when the baby comes since you won't be able to be there 100% for her after the baby comes. It's just a fact of life. She will get less attention from you when the baby comes. She will be fine.
But like you, I worried about everything and thought for sure I was screwing up my son. That and the tons of Mommy guilt I placed on myself for no reason.
You and your daughter will get through this. Just try to get more involved with the everyday stuff. Think of it this way....you can spend your time doing the fun stuff with her...playing, cuddling, stories, watching cartoons, eating....while your helpers do all the yucky stuff like chores and errands.