I think this behaviour is somewhat normal considering your circumstances--I mean your little one has spent her entire life with you so far being there with her, and all of a sudden you are gone during the day when she is used to have you there. And 8 hours can be a long time for a child! But the important thing to do is to acknowledge her feelings and fears. She feels abandoned, and the one thing you can't do is push her away...she will think you are punishing her. But you can't function with her strapped to your leg either.
So the best thing to do is to come up with a "chart" of her daily activities. Plan out the day from the time she wake sup to when she goes to bed, that way she will know what to expect and when. (like naptime, playtime, meals, maybe art-hour, whatever you decide) It won't seem so scary when you leave because she will know when you are coming back and what will happen when you are gone.
Plus you need to desiginate a special time for just you and her. Write it down on the schedule and show her that this time will be for you and her to do whatever she wants, like reading books, or going for a walk...whatever.
And the whole nighttime thing....well, that can't go on like that. I mean having a baby in bed with you is one thing, but as they get older they become attached to that and cannot go to bed without company if you continue with it. The bedroom should be sacred to you and your hubby, and off limits for chillins, unless you are comfy with them sleeping in bed with you until they are 9 or 10
I think what you can do is maybe go out and buy a special stuffed animal or blankey that will signify the bond between you and you daughter. Just tell her if she is scared, all she has to do is hug her bear or whatever and it'll be like she is hugging you.
These are just a few suggestions...I hope they help! My heart goes out to you....