The Devil and demons?

Dear Christians, does the Devil or demons incite one to sin and doubt the lord or is some of it human nature? I get the feeling there is a bad spirit around me since I don't believe in ghosts I assume this spirit is some sort of demon. I am just trying to figure out if its a demon trying to influence me or it's just my mind? I have become extremely close to jesus but sometimes I feel lost, doubt comes in my mind even though I adore our Lord, I hear a little voice swearing and saying horrible things about Jesus when I am praying or when I am thinking about him.. I have stopped doing many things I use to, but what I am finding hard to do is to stop judging others. I feel there is something trying to influence me for worse, I know I am not crazy, well I hope not.. My faith keeps coming back when I feel him around him, I feel this warm happy feeling, sometimes I feel my heart is going to burst from the happiness and fullness our Lord makes me feel, Right now all i want to do is follow Jesus. I hate this world and what is in it. Some people have suggested I am getting obsessive in my thinking, but I am only following my heart and his will.. Anyone had/having the same experience? What should I do apart from praying for it to stop? I use to read tarot Cards but even when I did this I still believed in our Lord jesus, I don't read them anymore since I have deciced to follow our Lord. I stopped reading Tarot 3 weeks ago. Maybe this has something to do with the bad feelings I am getting? Please help.