As others have pointed out, make sure to have the valve perpendicular to the rim at all times.
Secondly you could try make some improvised padding around the rim hole, especially if the edge in any way feels unusually sharp to the touch (rough rim opening AND/OR rim-tape?). Use your fingers. Consider buying some new rim-tape/band. you could also consider to gently sand the edge of the rim-hole by hand. This would be at your own risk, but doesn't sound too risky with some sand paper IMO.
Thirdly, could you use a shorter valve? The indentation on the rubber on the valve (best seen in the 2. pic) suggest that the valve has not been at 90 degrees all the time (unless this is some manufacturing artifact). If you inflate with a hand held pump, a long valve will give you high leverage at the valve/tube insert point. Making it easier to create tears it if you pump with a hand held pump without steadying the valve properly. Preferably use a floor pump or use a car tire pump at a gas station.
Finally, consider trying a different brand of tube that might have a stronger design in the problematic area, and be gentle when installing/inflating the tube.