Re: Im torn :(
Mastitis commonly reduces milk supply temporarily, so you should be able to overcome that, especially if you can get baby back to the breast. You might want to consider an SNS to supplement at the breast--give baby a little bit of extra incentive to be at the breast, while still stimulating your supply and helping him re-learn to nurse.
If you find that you become uncomfortably engorged, you can hand express a small amount just to relieve the discomfort a bit. Your body will figure it out if you let it.
Catherine, tandem nursing mama to Preschooler Girl 9/08 and Toddler Boy 3/11
Breastfeeding for 4 years and counting!