The drogue's effect is typically negligible, or you need to reduce the size of your drogue.
In terms of your main not being large enough, if that's the case, then use something like a Tether to hold the drogue to the main part of the rocket. When the altimeter fires the Tether, let it pull a bagged main up and out of the airframe, then strip the bag up and off of the main, and let the drogue bring down part of the rocket, while the main does the rest.
Trying to use two parachutes at the same time, especially a drogue and main, is begging for an entanglement. It may not happen the first time, it may not happen the fifth, but eventually it will, and you won't like the results.
Play the odds -- two parachutes dancing around together is a recipe for disaster when rigged up that way.