Unfortuately you have a lot of issues to deal with and I hate to give you bad news but I would rather tell you the truth than sugar coat it and lie to you like real estate agents will.
1. You may have a legitimate certificate for a support dog, but you need to know there is abuse with getting a certificate. I don't know if statistics are available but people are aware that it's easy to get a certificate for a support pet because this is for able bodied people. If you're blind or in a wheelchair for example, landlords can see your handicap and you don't need an explanation to own a service dog. However, if you look "normal" and have a certificate for a support dog, every landlord will question whether the certificate is real or fake. Anybody can get a crooked doctor or somebody to issue them a document to apply for a certificate because they can't find a rental that allows pets. That's how much abuse there is. Of course, this hurts people like you.
2. SSI is a source of income and accepted BUT the issue is if regular rentals are $1,000./month without utilities, no landlord will take a loss of $450./month+ just to accept you. Landlords can find tenants in Grand Junction who can pay $1,000./month without utilities included.
3. You need to go thru the Housing Authority / Agency for Grand Junction and get them to help you. Is there a waiting list or subsidized housing?