Yes, exactly what FroggFrogg said. The only fish you have that should be in that tank is the betta. Some facts: fish
don't just grow to the size of the tank they are in, although their growth is stunted which is why people think fish only grow to the size of the tank they are in. You are presently killing both your goldfish and your scissor tail rasboras, read
the TFF newsletters myth of the month for more info..
Also your scissor tail rasboras are schooling fish, so should be ideally kept is sixes. They can get up to six inches each.
Regarding the goldfish, you
MUST read
this .
It's ok, most people make these mistakes when they start having fish(i started with 3 goldfish in a 5gal, until they started dying and then i researched).
Whatever you do, you must not listen to the advice from employees at big chain stores, or any shops that do not specialize specifically on fish. Even then, people are just out to sell the fish at the end of the day, so watch out. You made a very good decision coming here for advice, and your fish will thank you

.
Anyway more questions to help, how long have you had the tank set up? And did you cycle it? What kind of filtration/heating does it have?
For future reference, you should have one inch of fish(excluding tail fin) per gallon and no more, until you are much more experienced, understand how the nitrogen cycle works in fishtanks and have made changes to your tank to accommodate for this knowledge.
You should read all of
these too

.