No sex drive what's so ever.

My son is now 4 months old and I literally DO NOT WANT to have sex or even have the slightest dearie to have sex with my bf. Since my son was born it's prob happened twice. I feel so bad and I don't know if it's normal. I'm scared to have sex again and I don't look at BREAST for sexual favors b/c I breast feed and I pushed a baby out... I don't look and feel these parts as they should anymore and I feel like my relationship is suffering from it. I love my bf and it's nothing to do with him but has anyone experienced this before too? How long did it take to settle?