" I relocated from the middle east to south america with two babies 3mo and 22mo when the pandemic was in full swing, as a single parent."
I hope Blue Peter had the decency to send you a badge.
While we were all arguing about ferries from Oban, potholed roads, formula and island baby sensory groups in the middle of the night last night, OP was probably trying to get her head down for a bit of much needed sleep. If she has indeed set forth today, she'll be in transit now.
"it's just eating away at me that I've done something wrong in not immediately going and instead being here."
OP you did absolutely the right thing by waiting for the vaccines then giving the baby and yourself time to regroup after the recent journey and time away from home before starting the next one. 100% the right thing.
Maybe the journey will go like clockwork and you will be welcomed with open arms, the rallying island community will make a Trump MAGA rally look half hearted, you will be taken into the bosom of the Scottish family, your child will inhale the fresh air and start sleeping beautifully, your grateful husband will fall into your arms and view you with fresh love and respect, your FIL will be a lovely kind charming grandad and the sun will shine on your country walks and you will be spotting seals, humpback whales and feckin' golden eagles by the score in island splendour.
But...if the journey is awful and the weather is shit, and the walks are shit and a bit scary, and you feel trapped and ignored and bored and tired, and your husband fecks off to his laptop and your FIL is obnoxious, and your baby is still a sleep regressing baby, and you just get treated like The Uterus From Off, the empty packaging that the shiny new baby came in or at best the plugin battery charger for the new toy then...
...it's not because you are a southern softie, a wet week, an arrogant culturally insensitive English cow, paranoid, a cold hearted bitch, non resilient, selfish, needy, feardy or a bad wife. You're none of those things.
You are a normal person, and a good mother, in a shit situation. Remember that.
Good luck town mouse OP from country mouse me.