GIRLS LETS BE HONEST WHY DO THE NICE GUYS FINISH LAST? why should i not switch over?

im gonna make this easy. im a nice guy thats too bad because my girlfriend broke up with me. i didnt tell anyone about me and this girl being in a relationship because im a low key guy. the break up messed me up at first but im better now. people think im a huge player because alot of girls like me when i go out i always have girls showing intrest in me to the point where i expect it now. really this is not the case im actually not experienced at all maybe this is why my girlfriend broke up with me. never been a relationship guy but i made the exception for that one girl who actually cheated on me dumped me and when i stopped talking to her pretended she liked me and dumped me agin 10 times worse and then flaunts her new boyfriend in my face. thats cool because like i said im pretty popular have alot of friends and theres always girls that are interested in me im educated im 21 and have a job making $80.000 a year. the problem is that im REALLYshy.because of the way that my one time ex treated me i kindof have trust issues with girls but know that all girls cant be like this. 2 of my friends have had relationship problems in the past month and i helped them both get back with there girlfriends. the thing is that it seems that there is no one to help me, thats cool too i guess because i dont mind helping my self even though im always down to help someone else out. i dont want too hear awwwww dont worry there is someone out there for you that will appreciate you. i dont need to be lied too and its not doing me any favours by lying to me. you can never turn a bad guy good but once a good guy has gone bad hes gone forever and to be honest im thinking of switching over. SO MY QUESTION IS WHY SHOULD I REMAIN TO BEE A NICE GOOD GUY I REALLY DONT SEE THE POINT. WHATS THE POINT OF BEING NICE/GOOD IF YOUR GONNA GET TREATED LIKE ****?