Bridie.
I have had a uretheral catheter on around 12 separate occasions, I have normally tolerated them quite well. I have only had one uretheral catheter inserted while awake and in retention and it was not the best experience of my life but I would do it again.
Instilagel or hydrocaine can help with any soreness to the eye of the penis. Keeping the catheter from moving will also help with comfort. Snug bit not tight underwear helps and a pad in the underpants can also help. Having the right straps and fixation devices can also make a big difference to comfort. What size is the catheter, the info is on the coloured collar. A big catheter is going to be more uncomfortable than a smaller one, but the trade off is a bigger one drains easier.
I found lying down usually helps with the drainage process.
Make sure under the foreskin is clean a make sure it is pulled back over the head after cleaning. I had a situation where foreskin would not go back over the head and it got quite inflamed, my nurse advised me to use a bag of frozen peas on the penis to reduce swelling, then some lubricant to get the foreskin bag ove the head, of course as always if in doubt get qualified medical advice.
I also did self catheterization (obviously not while the catheter was in) and having the knowledge of how to perform it did take away the worry of going into retention.
Thanks Chris