Wheezing Help me please!

My guinea pig, Luna, has had this wheezing problem that pops out of nowhere. I've taken her to the vet and was told that it was probably just an infection. That was maybe 2 years ago now. She just turned 4 last month and still continues to have this problem so now I think its not an infection. She also has crusty eyes each morning, and recently I've noticed that instead of walking normally with her back legs, she walks with her front and hops with her back. She's also gotten a lot more mellow which I know isnt normal. Like I mean extremely mellow. She will just lay there pooping and end up with a bricked up piece of poo. Im starting to think this is a heart problem after I read this page. Do you guys think this could be possible? As soon as I get enough money shes going to the vet.

https://www.guinealynx.info/heart.html

2nd link removed by moderator.