Frustration and fishing go together like baseball and apple pie. They are joined at the hip. You can't have fishing without frustration; otherwise, they would call it "catching".
In my 8 years of carp fishing I have developed some techniques that help prevent that frustration from getting to the point that I don't enjoy fishing any more.
For me, I try to focus most on getting out of the house during months of nice weather, meeting new people, enjoying time with friends, seeing new places, traveling a little, exploring, visiting new cities, fishing in new locations, etc.
In my first couple of years of carp fishing, I focused a lot on fish size and less on those other things that help make the process more enjoyable.
Although it is certainly difficult, I try to focus less on catching my new personal best, a koi, a fantail, a mirror, etc. But I am certainly happy if it happens.
I spend all week at work dealing with a level of stress that melts away for 8 or 9 hours when I get to do some fishing on Saturday morning and afternoon.
As an example, I took the photo above while fishing. Photography and fishing make good companion hobbies. Fishing takes us to various urban, rural and city environments where we see unusual things like this bulk container vessel that is 600' long.
Ducks, geese, frogs, dogs, bobcats, dear, squirrels, etc. also make interesting photographs. I recently watched a squirrel swim across the small river where I was fishing. I didn't know squirrels could swim so well.