Just after everyone else's experiences as this is my first pg

For those of you who don't know I work in advertising in the city and sit down for the majority of my day taking phone calls etc.

In the last week or so I have been finding that about half way through the day the way bubs is lying is making in seriously impossible to find a way to sit upright without it hurting.
I've tried walking around, turning my chair around and sitting forward on it etc and nothing seems to work....and it hurts until I can get home and lie down.

Also, feeling very tired and cranky by about 3pm now to the point where whatever small amount of tact I possess goes straight out the window and can barely keep my eyes open.

Has anyone else experienced this and if so - do you have any tips or suggestions to get through it as I only have 6 weeks left until mat leave.

Thanks heaps All