Think I may have caused some damage to the urethra?

So this past weekend I was self pleasuring and using an empty toilet paper roll and a box on top of it that probably weighed a little too much. Then I ejaculated a second time Saturday and probably started well before I was ready to again as I went flacid relatively quickly. Now I can't really really get much of an erection although it feels like it is trying to. I did get a brief one but it didn't last for long after looking as some graphic images. Is it possible that I caused permanent damage down there? I want to have a family someday and this is very embarrassing. Is this something anyone has experienced? Please only provide serious answers.