Not an easy subject for us males but I think its worth discussing.

I'll get straight to the point and say definitely yes it has affected mine on both counts. There's been a definite lowering of desire for sex since I developed this around 2 and a half years ago. Even when I have a 'good' few weeks and there's barely any symptoms I don't feel half as hungry as I did. So I'm 45 and (thankfully!) not as thirsty as I was 25 years ago but the recent decline has been clear. Am reasonably fit for my age, can do 40 pushups, 50 sit ups in one go and can jog for 4-5 miles without stopping. Whether this is just a part of the condition or whether its knowing ejaculation will irritate things I'm not so sure. Maybe its the fact your 'bits' simply feel on edge a lot of the time? This has also meant lesser erections. More so in maintaining than initiating. I've generally been lucky and have rarely had issues with performance. ED is a listed side effect of Prostatitis but you do have to wonder whether its a by product of lowered sex drive than simply mechanics? I have been prescribed sildenafil 50mg by my GP and this definitely helps. In fact I'd say I'm more potent with this than I was without 10 years ago. So its reassuring that this condition (that makes you feel really un-manly) can be resolved with medication.

However, unless I'm really turned on or in the mood, the thought of having sex is all a bit apathy laden since I developed this condition.

Yes, this thing affects my sexual functions. I suffer from weak orgasms, low pleasure, weak erections, etc. It seems that in some cases it's related.