English listening and understanding the prepositions

While I'm listening to English, the most difficult part for me to listen is the prepositions. Even though I can understand slow native speakers, when it comes to the fast speaking, it is not only very difficult to understand individual words, especially, such as prepositions, but it also virtually impossible to separate words under certain situations.

What I'm currently doing is listening some lessons in https://esl-lab.com/ and do their exercises. While, following this tutorials, I've tracked down what are the areas that I cannot listen precisely. What I've found by analyzing all of the words that I could't understand before looking at the transcript was the majority of them are prepositions.

Please someone tell me what should I do in order to overcome this hurdle. Furthermore, it would be really appreciated if someone can provide me with some websites or online tools in which I can improve listening, especially the prepositions.