Maybe- not enough information to answer. You're the only one that can take temperatures IN the tank, where the snake is. And temperatures must be taken accurately- what are you using? What is the lowest (coolest) temperature & the warmest?
Makes a big difference how cold (or warm) the room is where the tank is too. And is the tank insulated to keep warmth inside the tank? or not? Is the air-flow restricted? or not?
You ask about the bulb wattage being "too much?" but remember that if this heat source is on top of a screen top on this tank, most of the heat is rising & not going into the tank where the snake is. (This is not the most efficient way to keep this tank warm.)
You say this bulb is new...what were you using before this? It's not the wattage that's important, it's the actual results you're getting in the tank.
And please tell me this bulb is regulated by a thermostat (preferably) or a rheostat (lamp dimmer) for safety???