I wouldn't borrow trouble before you needed to. You have until, at the earliest, October 31 before you need to really start changing your current routine.
If you the only reason you are working is for insurance, perhaps you could look into other options. I am also the insurance carrier for our family and lost my job last year. It took a while for me to find a job that I like and worked for my situation. I ended up putting myself and my husband on a medical "discount" card and got my daughter onto the state insurance. That allowed me to take more time and find THE job that worked for me and my family.
As for nursing - simply do what you feel is most natural. I strongly advise not going back to a bottle. (My daughter went straight from the breast to a sippy cup as well.) Actually my daughter totally refused to drink from either a sippy cup or a bottle when I first went back to work. I remember it was a rough transistion for both of us. But she was 9 months old at the time and was eating some cereal and other beginer foods - so I just let is go. I knew that she wasn't going to starve to death for the 6 hrs a day I was away from her. It didn't take long for us both to adjust to where I would just nurse her after work.
BTW - we didn't wean until she was two years old. There is no hurry to start that unless it is what you want - even if you are working.