just a broken heart need female advice

HELLO TO EVERYONE, english is not my mother language so ignore possible grammatical mistakes)

I was in relationship with my ex-girlfriend for 3 years.
It was fantastic for 2 and half years in relationship, because i felt in love for first time, and she loved me too, i always was so nice, i was protecting her of everything, i treated her like princess, we always go out together on coffees, launches, dinners, movies and etc. For 2 and half years we spent so much times she was happy i was happy. I thought that she is girl of my life. I trusted her soo much, my plans in life was with her. I never cheated on her.
And than for last half year everything went wrong. I am local politician, and young party leader, i have to got controls at my hands for elections, for young actions, for group meetings, for individual meetings and etc. She started to not trust me at my work and was against that. Also i am student. So i have not so much spare time but i always will find for her without distinction am i tired, am i need sleep, am i with problems or something. All i wanted is she to be happy with me. As time was going on, opposition social medias and portals started to attack me with bad habits, like taking drugs, paying others moneys, manipulating, going at casinos, and going with other women ( but i have not idea about all of this, everything is to get black among peoples for bad reputation).
She didn't believe everything but just for that women. We spoke both of us month ago, I explained about my upper situation, and she just said OK, it's fine.
Three days ago, i was in other city for some meetings, it was day of our anniversary . We phoned each other and it was everything normal at the morning. I come home after evening and take some food to prepare for dinner and celebrating 3 years of our relationship, while i phoned her she said that she is with her friends (very jealous friends on her for being happy with me, because they cant have relationship longer than one month) and with sad voice said me i cant speak, i will text you for minute. When I received message it was very big disapointment for me because she texted me with breaking up, all because she is not happy with me anymore, she lost love for me and feeling strange when she is with me all because i was accused for that woman, who i dont have idea.. I felt like word ruined and my life is over. I started to bother her and beg to dont do that. But she said No and NO. The Next day we meet each other and speak about problem,and again she is telling me that problem is in me. She said me again she cant love me anymore and and feeling unhappy with me, but she will consider herself about us. I let her to think twice about us, but it was very strange for me, how she loved me so much and immidiatly that stops, we are breaking up but the girl who I still love is leaving me like nothing happened before. what is the problem I am still thinking, breaking up with no reason, after all I gave to her, all I spent for her, all I wanted with her, all I dreamed for her. Today she called me, to tell me that she is sorry about hurting my feelings, but she really doesn't know what to do with us in future. I asked her does she has other guy, she told me NO, never kissed, never texted, never had sex with other, but she has in mind other guy, who she likes. I understand her but asked her again is this real, she started to cry, and continued to tell me that she is guilty for this, she is sorry for everything. But for what? For breaking me up and liking other guy, didnt want to tell me for what is she apologizing. So i started to doubt on her that she cheated on me and doesnt know how to tell me and she express feelings with crying and admits for just 'l likes other guy''.
So what to do,can i trust her with these my pains.Are there chances for cheating ?? Should I give her second chance for playing with me or she does not deserves??