Long story short, my car won't start.

I just had what I thought was an electric issue with one of the horns. It randomly started and wouldn't stop unless the battery was disconnected. This was also killing the chance of my car starting somehow. So I disconnected the bad horn and my car started fine.
So I turn the car off to fully connect the battery, and after I did that and shut the hood, the impact made the same horn issue start again.
So I disconnected the battery to turn the sound off, then I disconnected the other horn.
The car won't start now though. I tried jumping it too.
The lights and radio work fine, so the battery isn't dead, but the car won't kick on while trying to turn over. The turn over is very slow and there is something that goes "Tsss" when I stop turning the key.

Any advice?

 

Is there some kind of alarm system on this car?

 

Well, I found a very non-professional solution for the time being.
It turns out that my horn was shorting out, causing the horn to activate and pull all of the battery energy towards it instead of the rest of the car.
I disabled the horn by unplugging the electrical components and now everything is fine... except my battery is nearly dead (I've had to jump it the last two times I've driven it).