Tips and ideas about going out to appointments with toddler?

I have a two year old son and a two month old daughter. When we're at home my son is pretty great, of course he still messes in things he's not supposed to from time to time. When we have appointments to go to he becomes a whole different person. For example, I had an appointment and I'm sitting there trying to talk to the lady, he did not want to sit still. Starting throwing a terrible tantrum, throwing his head back on me, kicking me, biting me, nothing I was doing was making it better. As he screamed to the top of his lungs I tried giving him my phone he threw it, my keys threw them, cracker's started throwing them on the floor. At one point I just broke down and started crying... I just felt so defeated and like a horrible parent. He's done this when his sister has appointments too. The only time he doesn't is when his dad comes with us, but he can't always come. Any tips or advice on what to do when appointments come around would be greatly appreciated. It's getting to where I dread knowing there's upcoming appointments soon. Also maybe relevant, he doesn't speak much at all. He has an upcoming speech therapist appointment. Sorry for the wall of text, on mobile. via /r/Parenting http://ift.tt/2aCsluH