Should I put my cat down?

My 13 year old cat was diagnosed with diabetes a couple of weeks ago. The doctor gave me the option of putting her down or putting her on insulin. I chose insulin. It is very costly at $112/bottle plus needles and doctors visits. I have to give her shots every 12 hours. She was urinating quite a bit but it has improved with the insulin. The problem is that I am a single parent. I travel for my job. I don't have a schedule that allows me to be on time with the shots. I'm changing her litter box completely everyday because she urinates so much. I've switched to non-clumping b/c the clumping was sticking to her paws. With so much urinating I'm sweeping and mopping everyday b/c she's tracking cat litter throughout the house. I won't allow my 4 year old to play on the floor until I sweep and mop daily. And nothing gets done until I can complete this task. It's taking a lot of time and is beginning to wear me out. I feel guilty for entertaining the ideas of putting her down b/c everyone says that this is a manageable disease but i'm finding it hard. All the sites I've looked at talks about the quality of life of the pet but I'm finding my and my child's quality of life is dropping.