It's possible both to be against the government debts & deficit spending, and to be against an austerity agenda. For example, one way to reduce the deficit and debt with minimal pain and austerity is to reduce discretionary military spending (which, for the US, is arguably what most of it is, in the form of overseas adventures and bases, and astronomically expensive weapon systems), and to increase taxes and/or other…
Make sure to think about what happens next after you do that. The money spent on military spending is huge part of the economy. Stop that and you'll have massive layoffs.
If this stuff was so simple it would be solved already.