You poor thing, and poor little lad. It’s hard, but you just do.
Try not to mull it all over - yes, I know it’s easier said than done, but the more you go over each event the more they stick in your head. The memories don’t go, of course, but in future years, they will just be ‘an event’, not consuming every minute.
You may have to see and hear things you cannot believe you’ll cope with. You can. Strong mama! I say this a lot, but games such as Tetris or solitaire really do help to move those memories to a different part of your brain. It’s a known ‘anti’ PTSD strategy. So, get onto those when you can.
Kids live in the moment, so once a procedure is done, make happy memories together: laugh, distract, more laughing. I cannot emphasise how much laughter truly is the best medicine.
My DD is now 25 and we have ‘our hospital’ memories, they’re mainly laughing memories now. She knows most of what she went through as a baby, and older, but my memories are somewhat more traumatic as, for example, I sat with her through one operation.
You’ve got this.