Grannylynn, I think you have to do this. Well done for booking your holiday and have no more doubts about doing it. I have a sneaking suspicion you feel some guilt too, but you shouldn't. You've been a good mother, and your irresponsible son is a grown man who has chosen his own path all his life, and relies on you and the state to bail him out. I bet you wished he'd chosen another course, because our children remain our beloved children till the day we die, and it's hard, if not impossible to stop thinking about them. Your selfish son must have caused you many sleepless nights.
My philosophy on retiring is "It's my turn now" to live life and spend money in any way I choose.I hope you can adopt it too, and do your own thing without any guilt or worries, knowing you've done your best by your children. You can't take your money with you when you pop your clogs, so go for it and have fun!
Have a lovely time in India, and report back to us. I have felt very inspired to go there by the TV travelogues, and the Marigold Hotel films 