STDs STIs?????

I didn't get any form of sex ed at my school that was helpful.. or at all really... but what they did say is if you get a sexually transmitted disease you will have it forever until you die and its this horrible horrible thing that makes you less of a person... now I 100% feel they were being dramatic but can someone please educate me. If I were to hypothetically get an STD or something can it be treated and cured? If I'm being safe when I have sex is it something I have to worry about destroying my life? I don't even know what the symptoms of these diseases are but according to my middle school you are basically set on fire.