Weight gain during pregnancy

Today is the first time I’m experiencing sciatic nerve pain and it hurts so bad and makes me feel so uncomfortable! I went from being 115 to 180 in 9 months and it’s definitely taking a toll on my body😩 Thursday and Friday I walked 1.86 miles and I think that’s playing a part in being so uncomfortable. Anyone else gain 60+ lbs and is it normal to gain so much?? Doctors don’t seem to be concerned so I’m assuming it’s fine/normal but my body just doesn’t know how to handle it🙃