Been badly cramping since 33 weeks, any advise or similar experiences?

I'm 35 weeks exactly today, this is my 3rd pregnancy. For the last 2 weeks or so. My belly is continusly dropping a very noticeable difference daily. I've been having cramping in my back more so than in my belly. When I stand up or walk around to much or am to activate I have ALOT of pressure. When I'm sitting or laying down in any position my hips feel like there is pressure or someone grinding something on my bone. When he moves or kicks it feels like hes going to fall through my vagina. So because of all of this I basically get up take care of the things I NEED to do with my day and then spend as much of my day in bed where it's the most comfortable. I have an appointment on Monday and am trying to hang in there till then but I'm not sure it's gonna happen.