While Rodja makes a strong point, and ideally taking the time off would allow for the greatest path to correcting the problem, I don't believe it is necessary to completely take 3 mos off... Or a reasonable request at least for myself personally. You just need to place more emphasis on correcting the imbalance, and accept that your going to lose some chest development. IMO you don't really need to take any time off from your chest workouts, you should just re-structure them. That is unless your experiencing considerable impingement pain or discomfort during any of those movements with lighter weight. Focus more on full ROM movements with lighter weights that allow you to get a good stretch in your pec muscles. You can increase the flexibility of a muscle group considerably just by increasing the range of motion during various exercises.
I would also bet that when you bench, you tend to flare your elbows out considerably, which incorporates alot of internal rotators, and can add to the problem... so correcting your form for a few exercises may be necessary too. You can search for some bench press form videos on this forum.