Help! swelling/pain issues?

I can certainly understand a tight budget. I just spent $5000 on the horse you see in my avatar this summer. But it really does sound like you need the vet to come out and take a look at him. I would not ride him again until you find out what the problem is as you may cause further damage, and certainly more pain. And he does not need that right now. He may not be showing any signs of lameness, but if he has a swollen hock, you can bet there is something going on there. Since none of us can see him, it really is the wise thing to let the vet look at it.