Disheartened

Nell has been lame on and off for the past year. She gets a little lame, it gets better, she's sound, she goes lame again, she's footsore, she's not tracking up, she's full of energy and eager to go, she's sound, she's lame again... I knew when I bought an older horse we would experience a few issues but for the first year I had her she was 100% sound. Last summer she suffered a tendon injury. The vet didn't pick up on it when she was lame and we only found out by the time the scar tissue had formed a bump on the back of her foreleg. Now I think our jumping career is over before it's begun. At first I thought it was being stabled that was triggering the lameness but now it seems to be after any jumping. She was sound so I tried her over a couple of small jumps after hacking yesterday and today she was sore again. There's no way we could afford any treatment and probably can't justify it. I can't afford another horse and selling Nell is out of the question. It just seems so unfair when I was just getting my confidence back and Nell was improving. I can still hack her to my heart's content but with so little soft ground and Nell's intolerance to the hard, I wonder just how much fun I will be left with when I'm wondering if she's hurting. So I'm feeling down and a just a little bit lost at the moment...