Hi Holly Not good that your feeling nauseous.
When I changed from tablets to be njections the RA team advised me to increase my water intake the day before and the day after injecting mtx .
The amount I drink on the 2 days is 3 litres which sounds a lot but with tea intake ( for me anyway ) I can reasonably meet that especially in the summer when it is warmer.
It is worth you trying that because it definitely works for me.
All the best
Shy&retiring