I went through this myself with Spanish.
Here are some things that I did that improved my listening comprehension:
1) When you watch a Spanish TV show, don't try to understand entire sentences.
Just try to get your ears to "grab" words that are familiar to you.
All languages are repetitive, and certain words come up again and again.
Once your ears recognize those words easily, you can stop focusing on them and then move your attention to other words in the conversation.
2) Keep a notebook and a pen in your lap.
For every word your ears recognize as an independent word, make a slash mark on the paper.
(Even if you don't know the definition of the word, hearing it as a word separate from other words is a huge step in understanding)
Over time you will see the number of slash marks grow during an episode.
3) Write down any word that you want to look up later, especially if you notice that you hear it often.
4) Learn some of the "filler" words that are used. This allows your brain to skip over them because they arfe not important to meaning.
5) This is maybe the most important. Learn to hear the pronouns. Subject pronouns, Direct object pronouns, and Indirect pronouns. Hearing these and knowing what they mean will be a huge jump in understanding.
6) Rewatch the same series again and again.
After you know the story and the characters, your ears can focus on hearing the dialogue clearer and clearer each time. This really pays off.