Don't worry Lilly , this all sounds normal, everything is softening, and you will often get back pains in pregnancy, try to see how you sit, as i slouch alot or flump into the sofa, and I try to sit better now.
Not sure on the ribs, thing, keep an eye on it, could be muscular around it?
Oh dear - for the nasuea - hope it doesn't get too bad for you