Off to a Bad Start

I started a new PT job in juvenile corrections. I had to call out the 2nd day d/t a horrific migraine causing me to vomit. I asked supv if I could make up the day the next day, she said OK. Two weeks later I come down with a very severe cold. I'm in work and I ask supv if I could come in on thurs instead of wed to give me a chance to recover. She was hesitant but agreed that would be OK. Two weeks later I get the slammed with the FLU!! I sent an email explaining this and asking once again if I could rearrange days. The reply was "unacceptable....we've done this multiple times. Let me know if this job isn't going to work for you." I replied that I understood and that I wanted to make it work and I would do my best to be there. With a stroke of luck I improved the next day and showed up for my scheduled two days. When I saw the supv I explained that this was not typical of me and that it's been an unfortunate few weeks. That night I get a text from supv saying they had a call out and could I come in the next day. I replied "I really would love to but I'm still not 100%. Can you see if anyone else is available, if not, I will do it." 30 minutes later, she says no one else can do. My heart sank because the reality is that I was still really not well. I ended up calling her and saying, I really need time to recover, but how stupid did I look by saying I would do it and then saying no? Truth is, she hadn't really contacted everyone else and so I feel like she was testing me. Of course I'm feeling awful about how things have started off at this job. I guess this was more of a rant and the only thing I can do is try to prove myself going forward but it's created extra anxiety as I feel like everything I do will be scrutinized. Help!