Sore boobs!

So I haven’t exactly got much of a bust and with my first pregnancy I was hoping I’d finally get some.,. It didn’t happen. I didn’t suffer with them being tender or anything. But this time round OH MY GOD I’m in pain! I’ve already gone up a bra size and I’m only 4weeks. They hurt that much that the water from the shower (even on a low setting) makes me cry! Has anyone got any tips as to how to deal with it or help? X