I Cant Choose Between The Two

i had such a bad breakup with my last girlfriend i thought that i i couldnt feel and head over heels feeling again. so when i got with my current girlfriend , i looked at our campatibilty. enjoyed most of the same stuff, she was well raised and would make a good wife, a good mother and i would be content in have a 2 cars a house and 2.5 kids and be on auto pilot through life. we've been together almost 3 years and just a month ago i recently met and fell head over heels for a diffrent women, shes exciting and funny and i smile and laugh again. she knows about my girlfriend and still continues this relationship we have, she wants us to be together and tells me how much she loves me everyday and how im diffrent. she makes me feel good about myself. me and her talk and laugh about anything oppose to my current girlfriend who only talks about what bills need to be paid and how much money is in the bank. now im caught in the middle feeling guilty, i truly did not intend for this to happen. one of these women are going to get hurt and im going to be the cause. i truly do not know what to do, the best idea i got is to tell my current grlfriend and see where it goes from there. do i fight for what ive got comrfotable in? content or do i chase after something new and exciting? i just dont know