Sounds likd a helicopter with no speed

To whom it may concern,
Add ons. : Cone air filter,
: free flow exhaust,
:branches

The problem I am currently faced with is that I have recently towed another car and after about a mile and a half there was a sudden loss of power in the acceleration to which I thought was due to towing a vehicle. Then I noticed that it took longer than usual to pick up speed. So I decided not to continue towing any longer, started my engine and attempted to drive as per usual. At these moment my car had difficulty pulling off as well as low drive power with each gear change. And by the sounds of it my car no longer sounds as good as it did before. It sounds more like a chopper and the revs whilst driving sounds as though I am doing seventy miles when I am only doing twenty five.

Any advice or guidance please anybody?