I don't quite know what you mean by 5.3%, but I am going to guess you mean potential alcohol. That would put you at a very low gravity (1.040 ish). If that fermented down, it could be a little watery if fermented rather dry (one of my tricks on session beers is to mash REALLY HIGH to get a very high final gravity, like you would end up with in a more standard beer). If it is fermented and done (my guess) you may have just over-bittered it.
If it still tastes sweet and bitter, it may not have fermented, but at this point, something is bound to have started fermenting your wort.