FINALLY blood donation

Finally, after long wait I do the blood donation!
this is the first time in my life, because whenever I want to do blood donation there was a problem which made me could't do it...
First, because I just finish my period
second, because my blood pressure too low
third, because I am too close with my periods date

so, this month, I purposely count exactly 7 days after my period finish (clean) to blood donate.. and eat before donation, so my blood pressure would be normal, and that's it... I'm doing fine.
they gave me a bag of goodies, inside there were milk, biscuit and aqua (water) .. fair enough.

next couple of days I had a bit low blood pressure, when I straight got up I fill blank, so I need to get up slowly.. and when I get too many sun, i get dizzy faster...

so, what was my motivation...
First, I just want to try a blood donation, they said it's good for your health. esspecially i've got gout. when you donate your blood, your body produce new blood which suppose to be uncontaminated by any disease.. so maybe my gout can decrease, Second, is for my pimples, they said with blood donation you'll be able to clean your blood, and make your skin problem reduce..

after this I'll be able to donate again in the next 3 months.. so what happen if you donate less then 3 months? it's going to harm the donater and people in need.