50 shades

well here goes...... i have been with my husband a little over 3 years now. we have 1 child together and have set up a what seemed at the time the perfect family home. A problem started between us about 1 year ago when my husband was laid off at work his sex drive completly went down hill. he lost all self respect and didnt even bother to wash most days. he paid me little or no attention. He then suddenly developed a social life without me was starting to hide his phone came home late and drunk almost 5-6 days a week. This till the this day still remains the same. A hobby of mine has to always been to read and when a friend suggested i should read a what she descrtibed as a very thrilling book i picked it up at the book store. Since reading all 3 books i felt like i was missing out on something. i then joined a online chat room for s&m at first i was just curious until i started messaging with a master. i felt like someone was paying me attention and took the time to notice me. For the last 3 months we have started meeting up the sex is infigurating and to be honest i feel no guilt toward my husband. is that wrong? now the master wants me to sign a contract which makes me his and only his. I am torn should i leave my husband? is this just a fantasy that will end in tears? please someone give me advice am stuck i dont no what to do :(