go and see your gp, and insist they take you seriously if you hve to, and get a referral to a gynaecologist, as they (and not gps) are specialists in this area and will know what to do.
i had lots of problems with my stitches, all mine came out. mine was 2nd degree also, but the degree just relates to how deep internally the tear is, it was still a pretty long tear!
the things that made the most difference for me were a) airing the wound- sit without undies, on old towel if necessary and just let air get to it and b) salt water baths as suggested above. i bought a whole load of jars of coarse sea salt and put in a handful each bath, and did this at least once a day. also get plenty of rest.
the pain you describe is very similar to the pain i had, it wasn't in the wound itself but felt like it was almost 'displaced pain'. i had to have my wound cauterised- which is less scary than it sounds, over in less than a couple of minutes if that, and this made it fully heal eventually without restitching, which would have been the next step had this intervention failed.
you should definitely be on strong pain killers, co codamol and diclofenac are what they usually give if you're BF. also you can try instillagel or lidocain, these are topical ointments for symptomatic relief, available over the counter. its worth saying though, that even being this drugged up, i was still in excrutiating pain in my whole bottom area until i had the wound cauterised.and i had to have it cauterised 4 times in the end.
i spent many days crying so don't worry about that, just let it out... it was great for me to hear stories like those of PrettyCandles at the time I was suffering, as it helped me have hope that i would get better, which i did. 