I’d be a gibbering mess at those doses! 900 last night and 900 this morning? Obviously being on 600mg for 6 years you’ve developed a tolerance but please go to your dr and get some advice. Taking more will not help in the long run, you’ll increase your tolerance to it and then you’re going to start running out of tablets which will put you into withdrawal. You can not just stop taking this medication and withdrawal from pregabalin is awful.