Hi Chris,
I don't have the complications you describe but ISC (intermittent self catherising) for me is much more a case of mind over matter. The thought of sticking a catheter up my penis was difficult. When I realised I would have to do it four times a day I decided I just needed to overcome the psychological resistance. It now takes me five minutes in total and most of that time is washing. My key tips are:
Stay relaxed, tensing can stop the flow of the catheter.
Wash thoroughly using both hand wash and the antibacterial gel. I wash before I start, after I have got the catheter ready and afterwards. Infection is the biggest worry.
Slide the catheter in, it should be very smooth until it meets the sphincter muscle where there is a little pain, push through it, it stops quickly.
When it goes inside the bladder, you can see the urine emerge and hold steady until it stops. It's magic!
Then simply slide out in a smooth movement.
Wash agin.
Job done.
Occasionally there is some blood on removal, this disappears in a couple of uses. If it does not report it to your uro.
Occasionally the catheter does not work, I have assumed the suction motion simple fails. I just remove, leave it for a while and if my bladder is evidently still full, repeat. I think the odd faulty catheter is inevitable. I have had two or three at most.
Do not re use any catheter.
Hope this helps. It's part of my daily routine now, usually three times a day.
Happy days!