I know I am being annoying with my low quality coins, but would like to ask you again for oppinion on the reverse of this 19mm coin. Thanks!
Yes, the Phoenix is a possibility. The double diadem on the obverse bust suggests it is from the early-mid 4th century. See if you can make out any of the lettering. The obverse might be either D N CONSTAN-TIVS P F AVG or P F CONSTA-NS P F AVG. If that's the case, the reverse inscription would be FEL TEMP REPARATIO.
I cannot make out any of the lettering on either side of the coin and I doubt that I will be able to clean it good enough in order to make it reckognizable. Thanks for your help though.