On a carryover loss I would be getting a credit of $3000 how much would this affect my return in dollars.

[fanfare]

impossible to say without seeing your tax return

[fanfare]

you are supposed to file Schedule D every year until you use up your carryforward loss.

[cyd1954]

you  got it; every year until you use up your loss.  But the rules have changed and so have the write-offs
everything has changed do to Trump! you loose 

[fanfare]

The rules for capital gain carryforward have not changed.

It is not a credit.

If you are in the 24% bracket your max loss deduction is worth:

               $720