I need advice. This might be long..Taking AJ to the Dr has always been extremely hard. He's fine in…

I need advice. This might be long..Taking AJ to the Dr has always been extremely hard. He's fine in the waiting room but as soon as he sees we are going into the actual exam room he freaks out. I mean screaming at the top of his lungs. Even if there is no nurse or Dr in the room yet. Both the Dr and I figured it's because he knows he's going to get shots. He hates the table. It takes two of us to hold him down to get his hight and check him over. That was the only place this would happen but now it's getting worse. My grandma has to take him into her house using the front door because if she goes in through the garage he freaks out and hold onto her for dear life and screams. I went to the welfare office the other day and as soon as we walked through the door he was terrified. I have an appointment with WIC today and he has to be there to check his blood for iron levels. I'm having so much anxiety over it i told them he's going to have a really hard time and the lady said they deal with it a lot but I don't think she realizes how bad it is. Has anyone ever delt with this? Idk why he has such a hard time. He's never gone through anything traumatic so Idk what's causing it. It's hard to talk to the Dr about my concerns because we have to yell over his screaming to talk to one another and she has a very thick accent so it can be hard even when I don't have a screaming child in my ear. I don't know what's going on with him but I'm beginning to get pretty concerned.