I'm worried about my cat.?

I just posted a question about him peeing on furniture. I got responses about him maybe having a urinary infection. Also, I got responses about getting more litter boxes. Well I have more litter boxes. His pee has a bad smell to it (like onions). I've noticed this for probably two months now. I was supossed to take him to the vet to get a urnialyisis but something came up. Now I'm hearing that if he really does have a urinary problem if left untreated he could die...especially since he is a male and they have high risk. What do you think? He is peeing on my leather couches, his pee smells bad, he meows before he goes to the bathroom and when he drinks water, he only pees a little bit, not a bunch. What is wrong with him? Also, since I've waited so long to do something, is it to late to treat him if he does have a fatal urinary problem? I'm scared. He's my precious kitty.