Weight loss - 22lbs in 5 weeks
 

is that a good/safe rate to be losing weight at?

Bare in mind, I am trying to lose like 100 lbs, so I have a long way to go and I'm guessing at the start the weight always does come off pretty fast.

For the start (especially since you are looking at losing 100 lbs) this is normal. Your water and glycogen loss has accounted for a lot of that (which is why so much was lost so fast). If that wasn't the case, I would say that you are losing it far too fast for my liking :). You should start seeing a dramatic slowdown in a few weeks and will most likely see about 2 lbs lost a week. Keep it up Strange Famous, you are doing great!