First timer needs some help!

I read somewhere that if i want higher alcohol content then i could add sugar when the bubbling stopped.

Well, after about 4 days all bubbling stopped so i added some sugar(about 1/4 cup for my 1 gallon) and as soon as i did it bubbled up and shot out the top. i lost about half of my brew because of it. Since then i have seen no bubbles.

So my question is, is this normal and is my brew ok?

The sugar acted as something for all the dissolved CO2 to grab onto, thus creating a sudden gush of fizz. It’s just like shaking up a soda before handing it to a friend. Or putting Mentos in your Diet Pepsi. It will be okay, but next time you will want to dissolve any added sugars in a little hot water first, then pour this dissolved solution in your cider, and then this will not occur. Alternatively, just add it before fermentation begins (and thus there is no dissolved CO2 to fizz out).

ok. so should i add some more cider to fill it up since it is so low now, and just it finish?

That is a great idea.