Rear deraileur in wrong position

[Biker2772]

As Ian says: the chain is too short and this is causing significant problems when the OP is in the largest ring. There is a danger of catastrophic rear derailleur breakage (and more) with a chain this short.
The OP doesn't say how they know their freewheel is damaged but the straightforward solution is to replace the freewheel and chain at the same time. Until then I'd advise never using the largest ring.

I am going to be replacing the freewheel with a new one as well as the chain and rear derailleur.

 

[classic33]

I am going to be replacing the freewheel with a new one as well as the chain and rear derailleur.

Why, if it's working ok.
Third post questioned chain length, with others saying the same. Rear derailleur may just require cables tightening and limit screws adjusting.

 

[boydj]

I've just checked the 105 mechs on a couple of bikes. On the derailleur hanger there is a notch at the rear and on the mech itself there is a small peg sticking out which sits in this notch and stops the body of the mech moving forward. I assume the Tourney mech will have some sort of similar mechanism and this should be checked.

 

[Biker2772]

Why, if it's working ok.
Third post questioned chain length, with others saying the same. Rear derailleur may just require cables tightening and limit screws adjusting.

It was already adjusted by the bike mechanic. Also, the rear derailleur is slightly bent