It sounds like you tank is just going through a mini (though in your case a big mini LOL) due to recently adding new fish. I am assuming you added the dianos and cichlids in a matter of a week (give or take a little) ago. So this would explain why you have ammonia in your tank and why your water is cloudy. If you just keep up with those water changes as often as needed (just keep testing and don't allow ammonia to get .25 or above, nitrites .50 or above (I don't like mine going above .25 myself), or your nitrates get above 20-40 then you'll do fine. You've done right by looking for help and doing all you can to keep your fish alive and healthy
Very responsible!