Dad's condition

It seems to me things are going down faster than expected. I cant prove this yet but i am afraid that the MRI on the 29th will prove it. If I haven't mentioned it before, here's the story: On February 13th, after weeks of odd behavior and speech and three days of headaches so severe he couldn't work or eat, I forced Dad to the doctors office. They refused to  treat his "migraine". I took the nurse aside and told her it was more than a migraine and went on to describe his symptoms. She spoke to the doc and he said that the ER was still the best bet as they could run more test. At the hospital, I done the same thing, pulled the nurse aside and explained all the symptoms. Dad had no complaint other than a headache. Well, they ran a CAT scan and immediately started talking about shipping him to Erlanger, a much bigger hospital about 60 miles from here. They said they found a small lesion and a small bleed in the left frontal lobe. This explained the strange speech and mood changes. So off we go to Chattanooga, he in an ambulance and me in the car. At Erlanger that small "lesion" turned into a tumor and swelling on the brain, sever enough to shift his brain. He remained in Erlanger from the 13th through the 15th the came home the night of the 15th to spend my sons birthday with us and attend my middle daughters play. This is also the day the doctor told me that what he had was a GBM tumor, or glioblastoma. A little research and I was official freaked  out. Friday the 17th he went back into the hospital to have the 4cm tumor removed. I was so afraid that he wasn't coming out of surgery, but when he ask " Will I wake up from this?" I told him yes he would. When the surgeon called to tell us everything went well, he also informed us that they wouldn't actually know what it was till the pathology report came back. He also said that because of the area where the tumor was located, we wouldn't know till he woke up whether or not it would affect his speech. But he woke up asking for food and feeling fine. Things seemed to be looking up. He was cranky the next day but alive and having no apparent problems talking. There was a chance he would be fine. He got out Sunday night and seemed to improve as the days went on. Twelve days later he went back to get the staples out and we were informed that what he had was grade 4 brain cancer. Specifically Gliosarcoma. A rare and deadly form of aggressive brain cancer. Research says one year with good response to treatment. Now onto 6 weeks of radiation and chemo. Five days a week radiation, seven days a week chemo in the form of a pill taken at home. His doc tells us  3 to 6 months without treatment, 18 months with good response to treatment. But here we are, just over three months past discovery finished with radiation and starting the first round of maintenance Chemo, twice the original dose but taken only five days out of every 28. I'm worried that he is already having regrowth. He's tired all the time and I think his speech may be acting up again. Statistics say two year survival is 9 percent, five year is 2 percent. I keep trying to tell myself that what is terminal today may not be in 6 months, that advances are made everyday, and that someone has to be in the 2 percent so why not him? I know this is unrealistic however, and I ache at the thought of losing my Dad. I cant imagine life without him. I lost my Grandma in December ( my Dads mom) and it's still not sunk in. I cant imagine losing Dad too. And the wondering if causing me so much anxiety. On the 29th we go back for his first post treatment scan. I don't know what will be offered if there has been regrowth. More surgery? And if so, will he take it? I cant even began to wonder what it is like for him, but true to his nature, he don't let on to what he is thinking or feeling. Will he be here for Christmas? Emily's next birthday or even mine? All the questions are driving me crazy. And just like Dad, I hide a way my sadness and fear. I focus on his treatments. I make sure he takes his meds. And I try to keep him focused. Sometimes it all seems so unreal. Just as it did, ( and still does) when Grandma died. Then sometimes it hits me like a ton of bricks and I cant breath.