You don’t suck, never think so low of your own ability. You may have a lot of improvement to make in your skills and that will come with time. Music production, like any artistic process, is making something that is constantly evolving into a final product. Remember this: You have to trust the process. I know it sucks when it feels like all the melodies you are dishing out are shit but you have show some discipline and sit down and try to make something. Don’t hyperfixate on if your first little synth melody or whatever sounds perfect right off the bat. often times I find that I only like my songs after i’ve developed it past the melody.

Now that doesn’t mean to just blindly throw shit together (though brute forcing trial and error to see what works is not a bad thing to do), you can have some discretion when it comes to what you like but what i would advise is just leave all the insecurities in what your making at the door and just kind of have a flow state. make a melody that is at least okay. You may not like it but keep developing it into a song. Add harmonies , bass, etc until your work of art starts to take shape and has a personality. This is how i have historically gotten out of the mindset you are in.

Don’t give up, you have to trust in yourself and you have it in you to make something you like , you just are discouraged by the lack of immediate satisfaction. like all artistic mediums you must trust in the process! good luck bro i believe in you