You're taking it too seriously. I play against my best friend most of the times and he beats me most of the time too.
And technically i'm better and beat lots of people that defeat him frequently. I'd say i won 1 in 5 attempts against him. Lately, matches have been getting closer and closer and that excites me a lot
Enjoy that. It's a challenge. Just right after the match finishes and i lost, i can barely talk to him since i'm mad. Five minutes later, we're planning what movie we are going to watch later or which bar/pub we are going to hit
Tennis wise, I'm a brainless ball basher and he's a counter pouncher. If i'm 100%, i beat him. But when i'm not i'm done. From the emotional side, i'm too competitive and that puts lots of pressure on me. Perhaps yo're competitive too. So my advices 1) RELAX
2) Find a b*tch to beat. When my friend can't play, i call another friend who has never beaten me .. Life feels so good after every match
. And is not like you lose ALWAYS against your friend. If you make him play good, good for both.