Intrusive Thoughts.

These thoughts scare the crap out of me, like I am going crazy. I just recently started having these thoughts ago, i am not sure if the stress of scared of not being able to pay my rent since I quit my job or all the stress with my roommates caused them to come back, but I think quitting smoking and forgetting to take my lexapro for over a week helped in this regression. These thoughts scare me, I remember getting so scared of seeing anything sharp, scared I was going to pick it up and and just stab someone. or I was going to sleep walk and just kill people without knowing it. The thoughts that I am going to "snap" or "go crazy" and not know what I am doing, it scares me. Then i start thinking what if something else is wrong with me, what if I am Schizo or something, that scares me more. Lately the thought of "what if I get possessed by a demon", I know that it's just my intrusive thoughts. Has anyone else had those thoughts? I feel like I am the only one with these thoughts and that scares me anymore. My doctor recently switched me to 20mg of Paxil and o.5 of ativan(to take as needed). Anyone can help?