My lovely nearly three year old rescue cat has been with us a few month now, and is gradually becoming less stressed - he was at the rescue for nearly a year and as such he doesn't like going outside.
He does, however, sit on the windowsill and ask to be let out so we've started letting him in the back garden, where he'll stay for a couple of minutes then come running straight back in. He is a chronic over groomer so vet advised to let him out if he wants to go, as keeping him in will stress him more.
Anyway, there is a cat across the road from us who is very friendly to us humans, but not so much with our cat - many a time we've had to shoo him away if he starts our cat wailing. Today this culminated in a huge fight and our boy has scratches all down his tummy, which are really visible due to the lack of fur. I've had vet advise on how to manage the scratches, but I'm really unsure about whether to let him out again 
He's been sat yelping at the window for hours, but I'm not sure his stress levels will take another fight with neighbour cat. But am I stressing him more by keeping him in? I'm a new cat owner so I'm really unsure as to what to do for the best and would really appreciate some advice please 