You need not worry about this aspect at all.
When I do the procedure I always ensure there is adequate pain relief (they are big on pain relief in the UK and the cath lab sister would always be watching the patient intently and if the patient were to wince ever so slightly the pain medication was topped up immediately).
At most you may feel some initial discomfort when the local anaesthetic is inserted.
Following this the rest of the procedure should not cause any pain at all though the inflation of the balloon can cause transient pain (ie a bit like your angina pain) for about 30 seconds.
Some patients experience pain due to spasm of the artery in the wrist but we can always give medication to open up the artery and relieve the pain.
You should be able to inform the team anytime during the procedure of any discomfort or pain, and your team will give you appropriate medication both for pain and anxiety as needed.
Your cardiologist will also be in conversation with you throughout the procedure so you are aware of what is going on and of course, you can always ask if you are not sure. The aim of the operator is to ensure you feel as little pain as possible and are comfortable at all times.
As for pain postop, well, with adequate analgesia, there should be none. You will have sufficient anaesthetic inserted before the procedure and this should last well after the procedure is over.
With the radial approach the sheath is removed straight away after the procedure and you are up and about as well. You do have a tight bandage on the wrist for about four hours before changing to a lighter dressing and this can cause some discomfort.
If you have the procedure done through the groin you may have to lie flat in bed for upto 4 to 6 hours afterwards with a bandage on the groin and many find this uncomfortable especially if you are not used to lying flat for long periods. A discussion with your team might help to find ways you can deal with this.