You are not imagining it and you are not being difficult. Document it and take the document in.

How do you tell the difference between the drug working and just a good week?

Test one thing at a time. It feels slower and it is the only way to learn anything. How long have you been on drostanolone propionate?

Stupid question: how do you know whether what is in the vial matches the label at all?

Photograph everything before you open it. Ten seconds, settles most disputes.