Yeah HockeyShark is right.. take easy. Your supposed to enjoy it not regret it. Try one or two fingers and make sure his hands are clean and nails trimmed. You can get cut up and then an infeaction. Also, guide him on what makes you feel good and you have to be lubricated. Weather is naturally or KY jelly. Completey relax and have your Vagina lubricated while he slowing insets one finger at a time. Jammimg his four fingers in there while dry cant feel pleasurable.. you want stimulation.
Hard with 4 Fingers? No wonder why you are sore. Give it some time to heal. you will be fine. Next time try 2 fingers at most, make sure you are wet enough, and guide him through what feels good..