Leg gives way/ can't put pressure on it due to sciatica

[emmiezebra]

Hiya guys, I am 14 weeks pregnant with number three I already have two boys aged 5 and 15 months. I had an emergency section with my youngest and in both pregnancies I experienced sciatica/sciatic like pain a bit but nothing like this. It is unbearable. If I am standing, sitting or laying down if I have done enough to trigger it it is there. By the end of a working day I find my leg giving way one when I get a shoot of pain and even have crutches now so I don't have to put weight on the right leg. I have physical therapy arranged, I am currently signed off work but only till Monday then I'm due back, I am So anxious about returning to work, it's a physical job that can't be adjusted to suit my needs, I honestly feel like I can't do it