DO NOT feed peas. Some people do, some people don't, I don't think it's worth the risk when you have epsom salt. Sometimes it just makes the problem worse.
Fasting him would be the best thing to do.. Betta do not know when to stop eating, and will eat themselves to death so you must be careful how much you feed. 2 or 3 small meals a day is better than one meal a day.
You should be able to get a 2.5 gallon glass tank at petsmart for around $15 plus tax.
I'm sure there are 2 gallon or bigger fish bowls available as well, if you like the fish bowl look.
You should be able to find a Tetra brand heater, for 2-15 gallon tanks, for $15 plus tax at Walmart.
Walmart also has a 5 gallon starter kit with a filter (but no heater) for around $30 if you have room for that

69F is REALLY cold. Even when he gets better, his colour will be bad, and he will just sit around all day and not do much.. If you upgrade him, with a heater, his colour will show better and he will swim around all day like crazy.
