Your parents evidently know nothing of such things. Panic attacks and a public-speaking phobia shouldn't be things belittled. My personal experiences that have helped, i get myself very physically fit in the weeks/days prior to the presentation, helps lower my resting heart beat as a result etc...also some visualization, i.e. deliberately raise my heart beat up just prior to the presentation (i.e. pretend that my name has just been called so as to start reading in class/do the presentation - a psychological mind game on myself as such), so that my body is adjusted to what it will be like, in a couple of minutes time, i.e. a high heart-rate, one in which the body will adjust to etc...make my nerves more controllable due to such visualization...
if such psychology and exercise routes don't work, go for beta-blockers. These helped enormously at times for me, but ideally, drugs are the last resort, but maybe you're at that 'last resort' stage already...with beta-blockers, they made me feel a tad drowsy at times and i often had to go for an afternoon nap if i used them in the morning for a presentation...to sleep off the drowsiness...