I had a si sacroiliac joint injection near my tailbone 2 days ago and ive been hurting sick to my stomach and feel awful, is this normal after 2 days?

NO: Very unusual to have pain in SI joint after that length of time. It may have been done incorrectly or may have been injected in a place that should not have been injecte. See your doctor promptly.

Unusual: It is possible to have a reaction to a corticosteroid injection, but I would be alert for some other cause.

Injection site pain: Injection site pain likely indicates a bone or periosteum bruise; this can trigger pain reactions of nausea and fatigue - like vaso-vagal or poly-vagal reactions; best move at this point is to rest, apply cold packs 20 min on - 20-30 min off, 20 min on, etc; Let the doctor know who injected you - rarely, an infection could complicate