That's exactly what I would have done Natty. I will walk away from my children as far as I dare if they are having a hissy fit. I am guilty of going out of their line of vision, although I wouldn't lose sight of them.
IMO its the only way to handle tantrums when they've gone beyond distracting them out of it. Attention feeds the monster.
It is so incredibly hard having them close together Natty. I look back and think 'How the Hell did I do that?!'. But whilst I was in it, it was head down and get through it.
Just don't look back with any regret. I felt terribly guilty for DS1 because I felt I'd taken his babyhood away somehow. Despite only being 14 months old when DS2 was born, he suddenly, overnight, became a toddler. Of course he wasn't, he was still a baby but seemed so huge by comparison. So I wasted lots of emotion feeling guilty for DS1 and not feeling enough love for DS2. But I got it back.
In a nutshell, don't beat yourself up! you are doing a great job, just remember to have fun not get bogged down with them.
And I hope DHs appointment brings some good news xx