Hope everything turns out well.
Is there a dog park in your area ?
If there is, it's a great way to gradually introduce your dogs to other dogs, especially if they have a small dogs area. Mine started out in such an area, but they were more interested in the big dogs, and it didn't take long until they were out in the bigger dog area. You can certainly keep him on a leash, although that tends to make dogs more edgy than if they were free.
If you don't have access, hopefully you can find a friend ( or make one ) with a dog, and let your chi get socialized with him. I'd try to get him around some friendly dogs asap.
Maybe go to one of the petstores that let you take your dog inside, and let him meet some dogs there, too.