we all have someone we miss especially when it was someone who you cared about, but this happens in every relationship and over time you will forget it. just takes time. just who ever this guy is if he makes you happy then be the best girlfriend you can be to him.
why did you get with someone if you arent over your ex.? sounds like your just using this new guy and you are going to end up hurting him...so for the sake of you 2 you should let him know how you really feel and for me the way i used to get over guys was to think of everytime they made me mad and what i didnt like about them and i would think to myself "ugh! i cant believe i was with that idiot!" haha
Try to forget about your old love life - if you do, then you and your new boyfriend can have great times together. If you still can't stop thinking about your ex, go visit him occasionally and everything will be fine.
Busy yourself with everyday life. It's not easy especially when there's love involved. Take it day by day and soon your heart will heal and find calm and peace within yourself. When all is well the only thing that will be left is beautiful memory of what once was