definitely the cialis, it has those effects if your body isnt used to it, as your body becomes more accustomed to it the sides lessen but if I take too much I still get them, to this day and Ive used viagra a bunch of times I cant get anywhere near a full dose it wrecks me but cialis I can handle a full pill no prob. Try it with food, it couldnt hurt. As for going soft thats unusual but cialis just picks up on what you wanna do, if youre feeling horny youll be good to go if youve got a pounding headache and clogged sinuses, feel flushed and overall shitty odds are you werent feeling horny and it just went away on ya. Once the headache subsided im sure if you got back into it and the drug was still active if its legit cialis itd have you ready to go again. If you want to stay hard even with a headache go with the viagra. Cialis also wont prolong the fucking, just keep ya hard until youre ready to blow so if you can go 2 hrs youll be hard 2 hours, without cialis guys will go soft at some point if the fucking goes long, if youre blowing quicker than you want look into dapoexotine, its marketed for guys who blow in under 2 minutes but supposedly a regular dude on it can last easily an hr + with no urge to bust, doesnt keep ya hard the way cialis viagra does lowers the sensation response to the brain so you dont feel the urge to let go and cum. I havent tried it so I cant speak from experience but I know the site I use sells it, so maybe when Im back ill grab some and post feedback. Cialis and dapoxetine should make you able to pound till your body gives out.