Was my PRP under eyes technique normal?

When PRP is concentrated, it can cause a warm, burning sensation, which is perfectly normal. Gentle rubbing or massaging is okay for dispersing the PRP around the under eyes.  PRP is great by itself for an under eye brightening treatment. If you are seeking volume in the infraorbital rim of the under eyes, do consider mixing PRP with Facial Filler. Best,Dr. Anil Shah

Though I have seen it taught this way and it is one method to deliver and manipulate Prp, I do not think it is the best way to achieve the desired effect (thickening of collagen in the under eye area). 
There is no need to rub aggressively. Medium pressure and light massage will help spread the Prp evenly in the area. 
Cannulas are safer if you are injecting deep under the eye but you don’t  want to put the Prp into the subcutaneous fat or over the bone like a filler since it is not going to act like a filler and it will only stimulate regeneration in the area that it is delivered to. I inject just beneath the skin with a 30 g needle then with light to medium pressure massage it into the trough. A cannula is big and bulky and meant to avoid penetrating a vessel when injecting deeper (where you inject fillers) but is not necessary for the location the Prp is delivered to. 
Concentrated Prp can burn and be painful when it is injected. If the anti coagulant is acidic then it will burn more and there are techniques to reduce this burning like using a different processing container or adding a small amount of bicarbonate.                      
It will also hurt more if there are more red blood cells and especially for facial Prp there should be minimal red blood cells because iron is inflammatory to the skin and inhibitory to the regenerative process. 

PRP does burn when injected especially when activated by Calcium Chloride. It is normal to massage the area after the injection so that the fluid is distributed evenly before it gels.