Thank you all and thanks Squilly! But, I'll take harsh yet correct advice over no advice any day.
So here is the situation: I don't know s#@t about bikes; I'm only trying to ride one across Asia overland

I picked up a low mileage '03 AT in Thailand about a year ago, and so far so good, which is to say a few hiccups but nothing major. However, when hiccups do occur, I tend to freak the f%$k out because it could be anything.
Unfortunately, I recently got a surprise notification from the Indian Gov't which stated that I need to get my bike out of the country in a week, so I'm making a b-line to Nepal all the way southern India. Thats when the trouble started. I don't have time to stop.
I did 1100Km in one go two days back, and thats when it really started so sound awful. I checked the teeth on the rear sprocket this morning, and for the first time ever they suddenly looked worn as hell. I DO know how to adjust / oil the chain, so its been getting extra good lovin.
I'm 600km away from the border and things went okay today. I thought I might pick up a new chain in Calcutta, but I was there for 3 weeks not long ago looking for tyres, and other parts. Everyone just laughed when I asked if they had a chain that would be workable for the bike. Nobody knows anything about big-bikes there, even if they claim to. Either that or I was just talking to the wrong people. In retrospect, I wish I had done more of the work myself.
Aaaanyhow, I do have a front sprocket, but when we opened it up to remove 2 links from the chain the mechanic said it was fine. Oh well.
This "525 pitch/ 124 links" information is huge btw.
So, new plan: get the bike to Kathmandu, order parts, and do the work myself. I just hope it makes it. I hate to be putting this much strain on my bike, but unfortunately I don't see any options for the time being, assuming the bike will make it.
Its due for an oil change, which I had all worked out in Chennai, about 1800km ago, and was chasing down leads on a chain, but no more.
One thing of note: for the first time EVER the oil level was running low - totally dry dipstick unless I screwed it in one thread, or leaned the bike towards the dip-stick ever so slightly. So not totally empty. 400Km later, and I needed to lean it a bit more (ie it was continuing to burn oil, which makes some sense: it was on old/ 12k km semi-synthetic oil, running at highway speeds for 14 hours in one hot day, with a full load, a bad chain/ sprocket/ and knobby tyers on the front wheel.
I got nervous so I googled the pro's con's of adding a different oil (I had forgotten the weight of the oil I already had in there) and found the same brand (Motul), but it was full synthetic (specifically for 4-stroke motorcycles) and I dont THINK it was the same weight (15w50 vs 10w-30?). The pros far outweighed the cons, but over the course of the day I ended up adding a full litre of oil! This is to a bike than didn't burn any oil when beasting over the Himalayas with me and a passenger all summer.
So that's got me worried.
"Also check your main drive bearing, but if the problem's that bad, you'd have noticed the oil stain on the ground by now."
Well I don't know what that is, but I'm going to google it now. I've got a vague idea and I'll take a look in the morning. I did a quick look for leaking oil this afternoon but saw nothing.
Thanks for the Singapore link. I shoulda been on here earlier, not listening to everyone who told me it will be fine, no problem, you'll get parts for sure in (insert name of next city with millions of people). Its India. You're lucky if you can find AAA batteries here.
Lesson learned. Hope I didn't/ am not destroying my bike. Gonna ride nice and easy to Kathmandu. Be there on the 20th.