Relax! Mine was 4 before she was fully potty trained. I was in the same boat - full time SAHM. I used to feel embarassed, because I thought I had no excuse.... I was home all day - why wasn't my little girl using the potty. (For the record, I have 2 older kids who were potty trained by the time they were two).
My daughter could care less about being in wet panties just like yours. She is also one of the most independent and stubborn people I have ever known! Finally I gave up trying and used some reverse psychology on her. I'd tell her stuff like "too bad you're still wearing diapers, if you used the potty, you could go to preschool". I also had a big gift that she really wanted that I kept in the linen closet in the bathroom. She knew that in order to have it - she needed to use the potty.
When it FINALLY happened, we had a party for her, inviting some close family and friends. They all knew why we were celebrating, and brought small gifts, we had a cake (should have seen the look the bakery-lady gave me) and generally made a huge deal.
She did it on HER terms, not mine. And she's day trained, night trained and hasn't had any accidents.