Allergic reaction to antiobiotics?

Since I was younger, I would get an allergic reaction to antibiotics. My lips would swell and my whole mouth would fill up with canker sores. Some are small, some are big, and some have little tags of skin that hang off of them. They bleed, and sometimes the skin will come off in patches leaving it raw until those spots turn into canker sores. I get them in my whole mouth and down my throat but not on my tongue. They get the worst overnight, they swell huge, bleed, and my whole mouth gets very dry. The next morning they are very bad but through the day, the swelling of my lips goes down, then gets worse and worse every night. I can barely eat at all with them, but I try to drink a lot of water. Also, they last for about two to three weeks. I am having this right now, but I haven't had any antibiotics. I don't know what is causing them, but I have a cold and a sinus infection. Last time I got this, I had pneumonia and swine flu, but thought the antibiotics caused them. I don't know if I just get them from being sick or what, but my doctors have no idea what they are. Any information is good if you have any, thank you.