When mailing in a 1040x do i have to send the amended dollar amount in with the form? or will it be taken from my next years (2020)tax return?

send payment. if you don't it could be taken from next year's refund, if any. but in the meantime, your bill will be going up due to penalties and interest.  since the IRS is far behind in processing returns,  if you don't pay now it could be quite a while before the IRS begins collection efforts.   in just 5 months penalties and interest will add over 25% to your bill. after that over .5% 

If you cannot pay the entire amount then pay what you can and they will bill you for the balance due + penalties + interest.