Congrats on necking your first dose. I recall the only symptoms i suffered early on, was a sense of tension and anxiety. Probably the same as you; anticipating with nervousness the dreaded and much publicised side effects.
I. Should. Not. Have. Worried.
Flushes tend to come in the form of prickliness; about 3 hours after a dose; lasts no more than 10 minutes; is not even uncomfortable. I still get them now occasionally, several months in. It is no fuss at all.
Let’s face it, what you will be left to deal with is highly likely, HIGHLY likely to be very minor. As said, a full belly will quash any gastro problems; so no runs, gurgles nor projectilings for you!
An aspirin before will help with flushes, heat, prickles, itchiness. If not, then take an anti-histamine whenever such flares up.
Sit back, relax, enjoy the day, stay occupied and take heart from knowing that you are able to do something about this shitty disease.