First of all, you're not a loser for masturbating. Gee, only, um... just about every other male on the face of the planet does too... LOL The act is so inherently biological for us that we should never be ashamed about this (the best is when you have a female friend who knows full well that you do it -- oh, the conversations that can be had..lol)
Anyways, about your problem. Not that I ever experienced finding stone-type things in my semen after ejaculating, but I have wondered the basic premise myself, if you can pass them that way, since I masturbate an average amount for a 28yo male, and I have had many kidney stone episodes over the last 3.5 years. In fact I'm in the middle of one now, being going on since July, but I'm finally having a procedure done next week to rid my body of them. Let me ask you real quick -- During the time of ejaculation (or even all other surrounding times), did you ever experience pain deep in your groin area and/or around your lower back area (referred to as the "flank", it's about the bottom 3rd of your back, each side, you have right flank and left flank)? I only ask that because, a very common sympton of normal kidney stone behavior is having building and then instense pain in the groin and flank area. Which side depends on which kidney you have the stones in (you could of course having them in both sides at once -- I've had that before).
But to perhaps give you a better direct answer, it has long been to the best of my knowledge that when you ejaculate, the applicable area basically closes itself off at that moment as to not let any urine come out. Forgive me, but as I write this, I'm trying to think in my head of all the correct parts of the anatomy,etc, that come into appropriate play here. I know that urine comes from the kidney, down thru the ureter into the bladder, then out the bladder, down thru the urethra and out the top of the penis. And obviously the final path that semen travels is also thru the urethra, as that's the only pathway out of the penis, but it's the part that connects to the urethra of where the semen is coming from, I guess that's the part I'm having trouble remembering right now.
You know what, I just remembered it was on this very board where I asked my question in the past that had to do with this. I'm sorry Mike, I hope I haven't confused you even more with my seemingly double-talk and being so wordy. Do this: do a search thru the Kidney Disorder board for my username, "tyler7", and among the threads that are brought up you should find where I posed my ejaculate question. There shouldnt be too many to choose from, as I've made the vast majority of my posts on the Pain Management board. (& I should've made the subject line blatant enough to be able to tell). I don't know, I guess I thought when I started to reply here that I'd had something better and more clear to tell you. But at the very least, it won't take you long to look up that old post, I remember that the person who replied gave me a simple and clear answer that seemed to make sense.
AND ALSO -- PLEASE GO TO A UROLOGIST!!
part should be the very least that you do here. Because, and I don't mean to scare you here, but if you did indeed pass kidney stones in your ejactulate, that is rather unusual. Go get checked out, and good luck