Hi OP, I'm sorry you're still feeling this way. I did comment before saying I had drank before I knew I was pregnant and that baby is fine.
I can see you're worried about the drinking between days 4+0 and 4+5. I found out at 4+4 so just before you. I'd also been on holiday, didn't spot my period was late. Here's what I drank from day 4+0 onwards (I remember because I was away in London)
Day 4+1 : beer, gin cocktail, absinthe (and baby is not green!!)
Day 4+2 : gin and tonic, cider
Day 4+3 : beer
Got home and realised my period was late, took a test, all is well. Baby is 10 months old, meeting all his milestones etc.
FAS is when mothers have drank an awful lot throughout the whole pregnancy. Women used to drink in moderation until quite recently. My own mom drank guinness, as so many women were advised to do!
I see why you have been encouraged to forgive yourself, but I don't think it's helpful wording, as it implies you've done something wrong which requires forgiving. Which you haven't.
I do hope you can relax and move on and enjoy your lovely baby when they're here.