1920 Amish built bank barn.

Hello everyone! We purchased a new property last january, which has a old bank barn. Barn had powder post beetles. We have treated he whole barn and even had them back for spot spraying. So anyone that has had them

before knows the damage they do. We need a main support beam replaced. Would be 12 x 12 x 35 is my best guess. Previous owner did support the beam but not jacked up where it should be so upper level has sunk. Another large support beam needs replaced below. Its more like an 18 x 18. Yes pretty large. So i am trying to figure out the best way to fix all these support issues. We do not want to lose the barn. Money being an issue, we may need to do it in sections. First being has the powder post beetles done to much damage to repair? We do plan on keeping up with treatment of them and yearly checks. After support beams are replaced will the floor boards in the upper level lose the bent memory and overtime lay more flat or will we need to replace the whole upper floor. These are the first projects we want to do. Last questions is, where do i find someone to look at my barn? Give estimates on work needed? Be honest on the whole structure? I have called 2 barn restoring companies. Both have said they are booked up maybe can come out next year. This barn is far from falling apart. Dogs play in it and we are not afraid of falling through anywhere. But we dont want it let it get that way either! Any thoughts or help would be great!