First time psychedelics (shrooms), two questions...

I have decided to try out shrooms for the first time in a few weeks time. I have used alcohol and cannabis hundreds of times, MDMA, about a dozen times, and have very limited experience with a few other substances (Ritalin, Valium, etizolam, cocaine).

I find that when I smoke cannabis nowadays I just become anxious and paranoid and rarely enjoy the high. Do mushrooms also have a tendency to make people feel anxious? If so, maybe I should not experiment with them. Also, would it be a good idea to have MDMA with me when I take the shrooms? I figure if I am having a bad time I can snort an 1/8th to quickly feel better. Furthermore, simply having the MDMA on me or nearby might make me feel more comfortable (knowing I can 'abandon ship' at any time).