Help - constipation and feeding strike

Hi! Lots of interconnected issues, I think and trying not to dripfeed...

Dd is nearly 7 months and has been a really crap sleeper for the last 3 months. She wakes me at least every two hours (and sometimes it's more like every 45 minutes) for various lengths of feeds. But her day feeds have become shorter and fewer. Today she's fed for maybe a minute in total in the last 12 hours. She's also refused to eat anything today. She's had about an ounce of water.

She's also fairly constipated. Only done one very small hard pop in the last 6 days. But she seems alright in herself and not in pain (except when she did that hard poo, sorry tmi). I've pretty much been feeding her prunes, pears and porridge oats in the last 5 days hoping to help her shift this shit.

She's also teething. Bottom two showed up about two weeks ago and top two have showed up in the last couple days.

I'm growing a bit concerned because she won't take more water, but her nappies don't seem as wet (but she has had wet ones today). And she won't nurse. Help! Any ideas of what I can do?

Is it just teething? Is this normal?