L.S.
I had a 4th degree tear and a lot (about an hour & a half) of stitches. They got infected, and I had to be readmitted for antibiotics and monitoring. It was pretty horrible.
My advice: get on a stool softener & laxative, and make sure you're having regular bms. Get a sitzbath, and use it, multiple times per day. Use a warm squirt bottle and witchhazel pads to cleanse & soothe the area. If you wipe and see green pus, or if you use a mirror and the area is really inflamed, see your doctor. Use your pain meds as prescribed, and if you don't have a prescription, get one. See your doctor a week-10days post partum to check for infection & to make sure you're healing well. Get a donut pillow to sit on when you're nursing. Give yourself time to heal - like 6 weeks. Like I said, take your pain medication, get some help to assist with taking care of the baby & your family while you heal.
On the plus side, similar to LivTokyo, I did not tear at all during the birth of my 2nd baby, and was healed with no pain really quickly.