Get a really supportive bra! Buys a new one-go to an actual lingerie store (preferably not Victoria's Secret-they don't train their staff to fit bras correctly). I like Bali & Lane Bryant. Get something with wide straps & just a little bit of padding in the cups (not push up, but extra support). All of this will help keep strain off the girls & will aid with sore/constantly erect nipples. I used to sell bras for LB & learned how much different a correctly fitting bra can help. Most women don't even know their wearing the wrong size bra!! Good luck mama, & congratulations!
Congratulations! I found baths to be relaxing and minimise the tenderness. :)