Can someone help me understand these feelings.

While I'm breastfeeding my nipples itch, as well as some parts of the skin on my breast.
After my boobs are empty from feeding or pumping, I have mild shooting pains at my nipples, sometimes at the tip and most of the time just at the areola 
And my breast have been warm to hot most of the times and I try to pump right away just to see if it changes anything but they just stay slightly warm after that.
Left breast has a huge let down, and can pump 3-4 oz 
Right breast can only make 1- 1 1/2 oz..the let down feels so slow and I have to stop pumping and for 3-4 min then pump again but it only squirts. ( anyone have any ideas to help there)
Overall I feel nervous that I could be getting mastitis.