uh oh, this doesn't sound good at all
First off, 10 gallons isn't big enough for your BTA--they're pretty sensitive creatures that don't tolerate fluctuations very well--and 10 gallons tend to fluctuate a lot in water quality/chemistry/etc. Also, your lighting needs to be upped. I actually never knew T-5 lights came at 8 watts/bulb. But even so, 24 total watts of light is extremely limited if you're gonna keep this guy in the long run.
As for the not-eating part, how long have you had him for? Bleached BTAs will usually eat, but if you just got him, he's probably still acclimating to his surroundings.... when you say that you "hit" the mouth, you're not trying to force food down his mouth, are you? My btas love silversides and peeled table shrimp fed in TINY pieces (think pencil eraser tiny!) every 2-3 days.
In all honesty, I think you should give this guy away/take him back to the LFS til you at least increase your lights. I mean, if you want to risk a 10 gallon tank temporarily, sure, but I really think you need better lighting.
Hope this helps,
Jamie