Massive swelling.. relief?!

I've retained water this entire pregnancy.. i'm 30 weeks now.. haven't been able to wear my wedding rings or anything but flip flops/slide ons for months. But, last night I noticed more swelling than usual in my feet/ankles/legs. My right is always worse than the left but last night I couldn't sleep well because it stung to lay my foot against the bed. Woke up this morning and it was dented deep (still is two hours later) and still tingly/stingy. I'm a stay at home mom and really lay around as much as possible because I really don't feel like doing much of anything else.. so it isn't from overuse. I know to watch salt intake.. i've had pre-eclampsia & just pregnancy induced hyper tension in previous pregnancies but my bp has been perfect, even sometimes low this pregnancy. My doc office doesn't have an on call nurse I can speak to so hopefully yall ladies have some insight..? What can I do to get some relief?