you don't have mental problems, you have a high libido and are obviously attractive. honey, there is absolutely
nothing wrong with that!
also: maybe one on one relationships are not for you, or not yet, you could be afraid of commitment, jealous for attention or just trully polygamous. some of us are and sometimes that's hard to figure out in a basically one partner kind of world mentality. only you can figure out what you want.
you love your partner yet you are turned on by others and fool around with them. then the guilt sets in.
don't be so hard on yourself, i know how you feel. i trully love my friends with benefits, but commitment with them has not worked out. am i waiting for the right one or am i afraid of commitment or am i just simply poly? after many yrs and relationships i've come to the conclusion that it's a bit of all these.
i love sensulatity and intimacy and like to give it freely when i want to, on the side i am afraid to feel trapped in a commitment and hate the responsibility, nor have i had one that has made me trully comfortable. so untill i feel like i am ready for one on one i'm gonna have fun. in the last few yrs i have learned to do it honestly....that way there is no guilt. and believe me, it's far from easy! you got to be very considerate of other's feelings either way! it's a juggle!