You drag your voice down to the point of being pretty flat at the end of every line. I think its a stylistic thing for you maybe or possibly for the song (i've never heard it before, not sure if its an original or cover), but you ARE falling flat so heres the thing.
Your singing without any support at all; the tones not placed or supported at all, so it falls all over the place as far as your intonation and the actual sound of your voice. I can hear that your jaw probably has some tension too, so i'll give you this exercise.
Hold your jaw down; don't force it down, just let it fall open and hold it in place with your fingers.
Now, sing "LAH GAH" (same sound as the word saw).
Your tongue neeRAB to touch the back of your two front teeth on the "LAH" and come all the way back down for "GAH".
Do this on 3 tone scales throughout your range. When you reach your break, just let it crack and go into falsetto, don't force it to try to keep it in chest for now.
Thats for jaw tension and releasing your voice.
Now, to place your voice, just hum on 3 tone and 5 tone scales, all through your range. Close your mouth, make sure your tongue is against the back row of teeth and not moving. Then just hum scales on "HMM".
As you go up, you should feel the vibrations go up too. As you get higher, you will feel the vibrations behind your nose (the mask of your face); this is the correct way to feel it. If your not feeling the higher pitches somewhere in your head, your not placing properly and you need to try again.
Thats about as much info as I can give without charging the consultation fee I have to do now since my income comes from vocal coaching haha.
That should start you off though. Do those exercises as a brief warm up before doing the song, then sing it again, listen back carefully to the recording and pick it apart and fix every single thing you don't like.