I thought I was going to die nursing towards the beginning with my 2 1/2 month old baby (he's my 3rd, so I wasn't exactly inexperienced). I have 3 words of advise for you.
1 - make sure the breast shield attachments for your pump are big enough! Your nipples may be larger than usual if they're irritated. I had the wrong size shields as I pumped with my first two kids, but couldn't believe the difference it made when up upped a size (or two!) on the breast shields.
2 - apply lanolin (not just any nipple cream - this is the only stuff that would be safe if the baby ingested it) BEFORE you pump. It protects your nipples from rubbing, or even just the push/pull of the pump.
3 - if you can find a compounding pharmacy around you (one that can actually MIX medicine, not just a reseller of pre-made medicine), have your doctor call in a prescription for Dr. Jack Newman's nipple ointment. This stuff was completely amazing, and helped reduce soreness, etc, along with any other issues with my nipples.
I swear these three things saved my breastfeeding relationship with my sweet little baby! I hope things work out for you :)