we have achieved a lot since 6 months where she was Co sleeping and feeding 6 or 7 times a night.
You have, without doubt. But if she was cosleeping and being fed to sleep only two months ago, it's unreasonable to think that comfort mechanism will just vanish.
How about bringing the cot into your room until baby learns to sleep through?
It seems you expected to go from fully parental comforting (feeding to sleep and cosleeping) to fully independant sleeping, without there being a transition period. As you are finding, your daughter needs help to adjust to this change.
if I keep bringing her in bed will this become a habit?
If cosleeping never was a habit then the occassional night, when extra reassurance is needed, won't be a problem. Different matter when cosleeping was a long-term habit and you are trying to break that habit.
Is there anything else I can do to help her?
Make sure she can find the dumny easily in the night, she can't put her own dummy in if she can't find it.
Keep practicing putting it in herself (in playtime put dummy year upwards on the floor, away from her. So she has to move to get it, pick it up, turn it around and over in her hands, figure out the right way around, put it in). She'll be on the cusp of learning these skills. It's a dummy game-changer.
Have more comforters too. Something that smells of you will be useful. An unwashed pillow case from your bed maybe? Or a Muslim square that's been in your bra. Much as it may not be convenient to you, it's you that your daughter wants to feel comforted, so things that remind her of you will at least give a bit of comfort.
Then accept she'll need comfort in the night from you, so make it as easy as possible for you to sleep while being there. So cot in your room rather than you having to get up. Cot within arms reach. Remove clocks from your room so you stop paying attention to the time since last wake up(psychological, but works to feel better rested). Don't count wake ups.
Can DH share the night time responsibilities once you are at work?
Then - adjust your expectations. Night wake ups in the under 1 year old are well within the realms of normal. Some babies will wake frequently. Many babies need parental comfort to learn to sleep deeply - denying it will just give you a light sleeper so ends up being counter productive.
In terms of the practicalities of work. You might need to rethink if of your baby doesn't fit in with your plans.
- Share night responsibilities with dh and both go to bed earlier to catch up on sleep.
- if you have to do the nights, change your routine so you maximise your sleep. Going to bed when baby goes to bed. This will allow you to prioritise being well rested for work.
- if having an evening with baby in bed is of more value to you then sleep, then reassess your priority to do the job you do. Maybe this is the marker for a (temporary) career change?
- Emply help if this is affordable. Night nanny, au pair, cleaner, ironer, cook.
- Use flexible working to change your working hours to fit in with your need to sleep.