I made some American biscuits & they taste really salty.... HELP!?!

Not sure re biscuits for americans.
Does the colour and flavour match the original recipe.
Don't try and make 'cookees' - i suspect they have a different recipe, much like Jam is different to Jelly.
Were they ships biscuits?
Icing might help but don't use frosting - it is very different. Icing is a lot smoother and tastier. frosting seems like concentrated sugar.

Self-rising flour contains added salt and baking powder, if the recipe you made called for all purpose rather than self-rising, then you should cut back on the salt next. Icing would probably cut the taste of the salt a bit (as would jam or honey butter), I don't know whether it would be worthwhile though (depending on how much salt you added), you may have to start over. If you do decrease any salt in the recipe by about 1/2-3/4 of a teaspoon.

self rising flour has some salt in it already so if you added the amount of salt called for in the recipe, it would be too salty.

I would put plain white gravy on them, not icing. American biscuits are like your scones. Plain white gravy you can make doing simple white sauce and adding pepper, herbs, or some spices to. But leave out most of the salt that I would add to it.

I don't cut the biscuits most of the time, I just drop spoonfuls on the baking sheet and flatten them a bit, brush with butter and bake.

Sounds like you added too much salt. If you used Bisquick - the salt is already added.
Icing on a biscuit...............guess it will work but a very strange combination. You normally only put icing on deserts.

You can't make them less salty. Adding icing would be a waste of good icing. When you make a mistake like that, throw them out. You can make some more with the right amount of salt.

It would and that's about the only correction you could make at this stage.

Maybe. But if I were you I would make a new batch and don't add as much seasoning this time.