Have you ever been in this situation? If yes what u did?

Me and one of my friend who is living in Himachal has decided to plan a trip to kasol and all the well known places together for around 6 months. Finally I booked non refundable flight ticket but unfortunately his mother diagnosed with uterus cancer and he might not able to come with me so now I have no option but to travel solo. I need advice what should I do this situation I'm unplanned and have no solo travel experience but wanna travel anyhow.Any tips will be helpful