Get a skidplate for next time.
If you have a body lift, install the tank higher...every little bit of clearance helps. Same applies if you can move it forward without hitting the pumpkin or cover.
Move the axle back if you haven't already. That also helps departure angle and keeps the rocks away from the tank.
If you need more capacity, you can go with the NWMP tank, but it's a LOT bigger than stock, so it's going to have less clearance than what you already have.