Italy has a questionnaire--informational only--which should help you. You may want to try it today and then a few days before leaving.
Here it is: https://infocovid.viaggiaresicuri.it/returningtoitaly.html
You will answer the question about "entering from" with either Germany or Austria, depending upon the last country you were in.
The second question asks you in which countries you were in for the last 14 days. In addition to Germany and Italy, you would enter USA, if indeed you were in there before your 7-10 days.
Based upon that--as of today--you would need the 72 hour covid test so would need to find a place in Germany/Austria for the test.
We got caught with the requirement at the beginning of September. I think Italy added the rule on 31 Aug or 1 Sept. We were leaving on 2 Sept and could take the test before we left but because we were spending two days in Austria, the 72 hours would run out before we entered Italy and we would have needed to get tested in Innsbruck on a Saturday. I was having such trouble finding a place for the test which could get it done in a day we finally cancelled the trip. The stress was taking away the joy. We are going to try again in May.