[Aquastar]

Please ignore the previous post, they aren't very nice to any one.

Your fish looks like he has SBD, don't feed him this week and dose Epsom salt.

You're tank is also to small with not enough water changes, please upgrade to at least a 2.5. With a heater of course, 72 is not warm enough for a Betta to be active and happy.

 

[Aquastar]

Any Pharmasave, or Walmart.
You can use it in a bath for your self to! So it's not just for fish!

I would work on getting a larger tank with a heater first though. Craigslist always has good stuff.