Ive been boxing for 5 months

Power and strength come from technique which translates into proper form and speed. Power is a function of speed and mass as it relates to acceleration. Increase either and you can usually increase power. Now, unless you add a bunch of muscle and can then get that muscle to react at the same speed as you are currently throwing, you're not going to increase either.

The best way to increase power is to increase your speed and you do that by ensuring your technique is correct. Use the pivot in your hips and bring the power up from the floor through your legs, hips, shoulders, and out of your fists. If that doesn't mean anything to you, look up the boxing tip on the site that deals with pivot power.

A well balanced weight transfer can also assist with your power. Throwing a straight right for instance, there is a weight transfer from the rear to the front foot to coincide with the punch. If your technique is wrong and that transfer isn't happening, you are robbing yourself of some available power.