Like you, I put a post on here asking for advice after being turned down 13 times in a row! - Nobody wants me :-( Advice for a first time house sitter?.
I updated my profile and I made it clear that “I’m a single, non-smoking, 52 year old regular guy”. My profile also says what my interests are, and some of my photos show these, as well as pictures with the dogs I’ve looked after. I kept applying and it worked. I had several sits last year, and have several lined up for this year, and have now built up my profile with some great reviews. I’m now contacted on an almost weekly basis by homeowners asking if I can sit for them.
So, don’t be disheartened, keep applying for sits and you’ll be successful.