my first experience DTD afterwards sounds like yours- painful! I spoke to the doc about it and they said what the PPs said, due to BFing hormones its drier than usual, they gave me a hormone cream to use, but I was too scared it would muck with my supply so didnt use, just lots of lubrication, take things slowly, keep up your pelvic floor exercises, I found DTD to actually be a lot more pleasurable for me afterwards too, once we got all that sorted out anyway!