The post you found is an old one. It would be great if you would start a new thread and introduce yourself. I'm glad you found us!
When I first started on the shots I reacted to them. The lowest dose they usually give was too strong for me! It took me several months to get up to the dose I currently take. The reaction to too high a dose should be a skin reaction - red wheal, itching.
They might have to start with just a few things in the shot, not everything you are allergic to in one shot. I get two a week in opposite arms. I reacted to each shot differently. I also had a lot of pain with the 5ml shots. My allergist allowed me to cut down to 3 ml, which is working fine.
I'm so glad I stuck with it! I have NO allergy symptoms from dust, mold, grass, tree pollen now.