I can write cool chord progressions but melodies get a little weird.
try starting with the melody, with words on it. Actually, forget that, ..... try this. imagine a scene in your mind. imagine a situation, in life. Any situation. just make something up. then sing something about it, coming up with the words and the melody at the exact same time, according to what it felt like to be in the situation you imagined. Then very quickly after that, you can add chords to what you sang, which i'm sure you know how to do by now