At your little boy's age, I would imagine that so long as you are frequently putting him to the breast your supply should re-balance. You're still in the early stages where your body will be sending signals for how much milk to produce, so the prescription of "bed, rest and empty breast" for mastitis should see you good again before too long. Sorry, but no BTDT experience of mastitis (thank god)
Hope you feel better soon. Try and take things easy - it may be your body signalling you to slow down a bit.