Been on 2.5mg for one week, but need to lose weight quickly. Should I take 2 doses?

I’ve been on 2.5mg for one week with no side effects thankfully. I haven’t felt much appetite suppression or reduction in food noise. Trying to persevere with a low calorie diet (I did cheat a bit yesterday as it was valentines!) and I know that will be much easier once I’m on a higher dose. I need to lose 6 stone and ideally relatively quickly, as I can’t get the treatment I need for my spinal disability or increase my prescribed painkillers at my current weight.

I’m thinking perhaps I could take 2.5mg for another week and then double the doses to make 5mg, or that maybe I could dose at shorter intervals than weekly. Has anyone done this before, or is it just a bad idea?