There are probably a lot more people on here in a better position to advise you, but I'll throw my tuppance in for good measure.
Are you bad? No, you are not bad. You do, however (in my opinion) need to understand how to use your voice. After all, it is an instrument that needs to be learned and mastered over time.
I'd focus on breathing correctly, first and foremost, from then you can build up some control and strength without knackering your voice.
Also...Valerie. You weren't quite singing the melody as I know it, but if you were putting your own twist on it, fair enough. I'd sing with some backing tracks to help yourself a little and then record acapella.
Most of all, enjoy learning to use your voice and have fun :)