Moving on

I was diagnosed four years ago with stage 4 melonma which spread to liver blood bones lung and lymp node, I had immune thereapy for this but got gbs and colitis side effect was also ill with infections liver and gall stones sepsis twice x I later last year received the all clear which is amazing but I can’t seem to move on I have ptsd quite bad but feeling guilty as I should be singing from the roof tops but definitely not, anyone else feel like this ?