As others have mentioned after you listen for a while you'l'll hear the same things repeated and that will make it easier.
But some controllers do talk at the stereotypical atc machine gun speed
Which ATC area have you been listening to?
Have you tried Toronto (CYYZ Pearson) ? The controllers there all speak at a normal conversational pace. In fact, one controller, who I believe has recently retiired, was nicknamed "Roj". He had a mild French accent, and he spoke *very* slowly, like he had all the time in the world, even when things where busy.
Stereotypical ATC - Airliner123TurnLeftHeading030Maintain3000ClearedForILSZeroSixLeftContactTowerAtTheMarker
Roj - Airliner 123 ....... Turn Left .....Zero ..Three ..Zero ..... Maintain 3000 ....................... You are cleared for the ILS for runway six left .... contact the tower at the marker ... one . one .. eight .. point . three .. five