lower back and hamstring pain

hello all, just browsing through the newsgroups and thought i'd post my problem to get some
opinions. so, for a few months now i've been feeling some pain in my hamstrings after sitting for
long periods of time. actually, it doesn't even have to be long periods of time, maybe after a half
hour or so, the pain will start to increase. but, when i get up and walk around the pain subsides.
i've also been doing hamstring stretches which also alleviate the pain. my lower back also tenses up
after sitting or standing for long periods of time. so, i've also been doing some lower back
stretches which help somewhat. one thing that is weird, is that the pain seems to move around over
time, and also varies in intensity. for example, a few weeks ago, the pain was less intense and also
isolated to my left leg. now, the pain is more intense and isolated to my right leg. also, something
that may be related. i was having trouble acheiving erections while standing up. the problem is
gone, i'm back to normal with regards to that. but, it was very troubling. i've got a CAT scan
booked for may, hopefully that will give me some answers. but, in the meantime, i've stopping
lifting weights and am trying to rest as much as i can. i thought i'd post something on here to get
some opinions as well. thanks in advance for anything thoughts you could share.