Well, it appears to be getting worse.. Duncan had thrown up at least 15 -20 times during the day yesterday while I was at work. It was all over the house, little puddles. It looked like he had one good one of whatever was in his stomach and then the rest was just water. He had also been eating my roommate's plant. I let him out and he immediately started eating more grass. He had terrible diarrhea that was just more watery than anything.
I had to go to my second job and my roommate was going out partying with her friends so I called my mother and she came over to get him and brought him home with her. I asked her to put a cup of food down but he didnt' touch it or the water. I did get him to swallow 2 Pepcids tablets before I left for work. She said he didnt' throw up or go #2 at all while he was at her house. When I got out of work around midnight, I went over there. He came to the door looking so sad and tired and weak. We went outside to walk around in case he had to go but he didn't. I dont' think he had anything left inside since he hadnt' eaten since Wednesday. We slept in my mom's spare room on a twin bed together. I felt him for a fever. He seemed warm on his back legs and the paws of his feet? This morning he woke up his usual cheerful self. He still had no interest in any food and took a small sip of water, which he threw up in the car on the way home.
I called the vet this am and he has an appt tonight at 5. They said I should bring him in right away but I couldn't get the time off of work!
Needless to say, I'm a nervous wreck. I do like his vet but since his last 3 appts have been "emergency" or short notice, I have to see whomever is available and it's been someone different the last 2 times. They are very nice and have a great reputation in town but I think they aren't taking me seriously. And Duncan doesn't do well at the vet, he gets nervous and snippy, so he doesn't make a good impression. Regardless, I will MAKE them listen to me tonight. He obviously has something wrong with his stomach, maybe damage from when he was a stray, or...I dont' know, I just don't know....I just want him well so he can enjoy his life. It's so heartbreaking to see him sick

Thanks for all the support through this everyone. It means more than you know. My life is so hectic, no one seems to want to take the time to hear about Duncan or have some consideration for my feelings about my baby dog...except Pet Talkers!! I get that "oh, it's just a dog" look all the time and that just makes me feel worse. So thank you to everyone for being so thoughtful and helpful.