Worst Moment- need some advise

yesterday is my worst day and i never felt like yesterday in my life. already said that my bf had affair with one girl in the year 2010 .after 3 years still he is doing same. i mentioned my doubt regarding my husband activities in the past few threads. last November he talked and texted (24/7) with one of his colleague. last thread i mentioned my 4 doubts.
1. yes he went with that girl and dropped in bus stop by bike
2.he used another Sim to talk with her during late night(November)
3.before i intimidated her he got her number in office
4.they used to talk over phone in the mid night(after he talked with me and hang up call by saying i am getting sleep)

now he is saying that they are just brother and sister. then i asked " what is the need to talk in mid night as a sister and brother?". he didn't send any single text to me but he did with that girl every night. we got married and he says that " if you give me some space i will share my feelings to you". she is my sister he says....why still i am loving him? is it my fault? do i love him or suspecting him more? do i need him or do i need to prove that he is cheater? now he says " if you still suspecting me i will go some other girls" and he added "don't talk rudely and just try to speak with more polite". i want to him to feel my worst pain. sometimes i feels like he lancinating my heart by sharp knife. i am loving him from last 10 years. why he hurting me for unknown person? why he thinks that she is best more than me??? is my suspicious character discovered him as cheater?

i don't want to leave him but i want him to feel my pain. what i should do? i know if i avoid him he will feel. but i cant avoid him. i think that if i moved away from him he will take advantage and moved with some other girl... please suggest me ... really am in bad situation..

...I still can't understand you. Or did you really express your feelings in your mother tongue and use Google Translate? It must be bad then :s