I'm 25, Male,
My acne was totally gone for few months, I didn't even care that much about it while I had it before.
Until suddenly (like 3-4 days ago) I started to fall in love with a girl I'm seeing regularly somewhere,
I took an appointment to go there again in a week and boom, It started with 1, and now it's like 7-8 of the white ones (small white ones on chin and a red one between eyebrows!)... possibly more until my appointment so I'm gonna have to cancel it.
I'm not sad or depressed, but a bit angry, it just doesn't seem a fair time to have this 
I'm shy and now with this I can't even go near her.
Has any one experienced the same thing? is it even possible to make it go away in 5-6 days if I go for "2.5% Benzoyl Peroxide" tomorrow?
Yo man!
How is it going now? It really sucks to have pimple/acne in general. When you dont have it at all and it just turns around and says "good morning, im back" before an important meetup sucks! Those whiteheads might be caused by stress/diet. Have you been stressing lately due to some reaons or have you been eating junk/fast food/dairy/cheese/hot food or something lately? If not, it might be the winter if you are living in a cold country - lack of vitamine D. To be honest, the cheaper the treatment is the better is it (with quality ofc). Try to apply vaseline on spots for a couple days and you will see an improvement. Then continue using it - before bed time. If you see no improvements at all then try BP 2,5% but it will be a longer journey for sure. Before bed use vaseline and drink hot glass of water with 1/2 lemon in it. Lemon with water can also remove your acne/spots.
Dont be depressed because of this, mate. Acne is an usual issue even though it doesnt seem like it. Noone cares as you do about your skin. You might think "Oh, he/she is starring at my acne" when you are out in public but people actually dont notice too much, they have their own issues. The less you think about it the better will it get - Mental health effects your skin. Try to be as happy as you can and it will be allright. I hope this helped, if not or if it did, let me know 
cheers mate