The suffocating is indicative of lack of fuel, air or combustion. Have you checked the spark plugs? If they look "blackened", they are worn out. If they are wet with fuel, the spark plug wires or ignition coils might be faulty, thus not sparking the plug.
Also check if the air filter is full of dust, that will restrict air flow.
I have had a similar issue on an old BMW, which turned out to be incorrect timing. That is extremely unlikely, but worth looking at if you have recently had the timing belt changed.
The fuel injectors could be clogged or faulty too. They are expensive to replace, you should go through the "easy" things before looking at them.