my fish is like floating it trys to go down but its tail goes up and it swims...

[Steven]

...down help how can i help her? she is floating kinda and she goes down and doesnt move but it breathes no i dont have a other tank just tell me if i can save it i need an expert dont tell me oh it will die i dont want it suffering and it is a fat dalmation and i think she pregnant how can i save her plz need good answers have no time