I think the phrase you're looking for is "beating a dead horse".

I'm really sorry to hear that you're hitting dead ends everywhere you look I'd keep trying at the health goal though, it's something healthy to work towards (Oh wow that sounds redundant).

Is there any chance that he just didn't see the text? I miss texts quite a bit... and I don't text with many people. Or I'll get a text when I'm really busy and actually don't have time to respond... and then forget about it until a few days later and go "OH oops". I find texts to be a rather unreliable form of communication... it's actually why I like it. If people don't respond I tend to assume that they've either not checked their phone, or checked it when they didn't really have time to reply. So when I get no response, I don't tend to feel bad.

Notice the word "don't tend". Sometimes I still do, and that's ok!