It sounds like you have tried all reasonable conservative treatments and will need the fusion in order to get lasting relief. Only you know if using pain management to delay the surgery will allow you to do all the things you want to do in the meantime. Keep in mind that a home move and an international trip will both put a lot of stress on your low back. It's good to get a second opinion when considering a major surgery like this. Ortho and neuro docs are both qualified to perform this surgery, so go with the doc you feel more comfortable with.