No bad habits She's telling you what she needs and your are responding. In time she'll no longer need the breast and happily sleep by herself. Sometimes there are things you can do to help this process along (Pantley's No Cry Sleep Solution has some good ideas), but when it's really intractable it's because this is what they really need.

Separation anxiety is often strong at this age - maybe give it a little time. Is co-sleeping a no-go for you? We've done it on and off, part time (as and when necessary) since DS was 8 months old. He won't sleep in a cot, but sleeps in a mattress on the floor (usually by himself, but sometimes he needs us).

Is she teething? Learning to crawl/walk or reaching other developmental milestones? These sorts of things all tend to disrupt sleep and make babies seek out comfort and reassurance more.

All the best~~