Come on Dave.
That chap simply sent a message to the forum to say he had driven down to Spain from the UK and arrived safely,
I am very much aware that you badly want to come over to your place in Spain but that chap was not in any way trying to cause you problems. If he got into Spain last night ( Saturday) maybe you should aim to do the same next week. Remember to bring your NIE. If you are stopped ,have a translated explanation with you Incase of a problem.
I believe you owe that man an apology. You are at your wits end, he meant absolutely no harm. I bet he wishes that he had never bothered to post his arrival.
Come on Dave. Everything will work out for you I hope. Yes, it’s true, it is possible that a border guard could cause you hassle but you must remain calm and say that you and your family are simply going home. Good luck and have a very safe journey.