All the guidebooks I've read warn me about my left-handedness in India. Apparently eating with one's left hand is considered really gross.

But I know that as much as I'll try to be culturally sensitive, I'll inevitably slip up. So I was wondering - in real life (as opposed to guidebook life) - does it really make a difference to the average Indian who I might encounter in a restaurant or hotel, as to which hand a foreigner uses to eat? Do I need to write a reminder on my palm and then sit on my left hand so I'm sure not to use it? Or can I just relax and instead spend my time worrying about the many other things I'm worrying about regarding my trip???

Yes you can stop worrying.
I have just returned from 6 weeks in India and was likewise worried about this one. No problem at all. I was in Indian style restaurants most of the time and no-one bothered at all. They would bring a spoon and fork on request when I found it just too messy eating with my hand!

As a tourist, no one will care. The only exception is if you visit a Hindu temple and take an offering from the priest, he will only place it in your right hand. For everything else, you will be fine.

i'm left handed and had no trouble what so ever...

Yep, relax nuts. Me too. The ONLY time it was kinda noticed was in very, very down market places. And I'm talking $1 a meal places... and even then, a smile, a shrug, a head-wiggle and a 'you eat youe way.. I eat my way' works a charm. It's a fair point to be concerned about tho', and 10/10 you for being aware of the issues. I've taught myself to eat with my right hand if there's no implements [with the help of a lot of napkins]. But frankly, the number of times you'll be eating down market, with your fingers is kinda limited... lol.

I should have done a better search, I now see that this topic has been brought up before. But thanks for the reassurance, my southpaw friends! Actually, I might be selling my ambidextrousness short, I didn't exactly starve when I fractured my left arm, or the time I cracked my left collarbone. Now, chopsticks with the right hand might be another story, thank goodness I don't have to worry about that on this trip!

Yes no worries. My hubby is LH & he had no issues at all.