Deb, that sounds like anxiety to me. I still am nervous when trying new medications because I have had reactions to some. That puts that idea in your head and then anxiety starts with symptoms and then the fear can swallow you up! I still won't take a new medication unless my daughter is home. Then, after I take it, I get watching a good movie, etc. When the movie ends and I'm still fine, I stop worrying and then am fine after that when taking the medication.
You will be better! Honestly. I sure am. Supplements don't worry me that much. Now, iron can be tough on the intestines and I have Crohn's disease so my doctor has me taking Ferro Sequels. You can find these at drug stores and they are over the counter. They are much more expensive but very easy on the digestive system. A box of 100 capsules is around $25 where I live. I wait until CVS sends me a 25% off coupon and I buy those then.
Take deep breaths. You will be fine. When you first start taking anything new, have a family member or a friend be with you for a while. Once you see that you had no reaction, you shouldn't have that much problem taking it the second time and pretty soon you will have no problem taking it. This is anxiety....which is fear. Read the scripture I have in my signature. It has helped me greatly over the years and perhaps it will help you too!
Feel better.
Sherrine