if miners abandon mining since the difficulty has raised so much, will the difficulty start to go down since there is not as much competition for the blocks?

yes, it would decrease, but a LOT would have to leave.

I've been at this for a couple of months now, but from what I recall there's to be a total of 21 million BTC generated, and that is to take 200 years. I'm not completely certain, but I thought I read that only a certain amount is to be allowed to be generated per week.

If my memory serves me right, and that is so, then that explains the extreme increase in difficulty. With so many people joining this mining operation the difficulty needs to increase and also the number of days between increases also needs to decrease. Otherwise we will have all those 21 million coins generated in quick time.

I might be wrong... my memory isn't very good