Obsessions are thoughts, and compulsions are behaviors. And they keep cycling.

For example, you have the thought (obsession) that you must make sure the stove is off, then you walk to the stove and place your hand on the on/off button (compulsion). After you do that, the thought (obsession) returns. And it keeps cycling.

You might want to look into cognitive-behavioral therapy (CBT). CBT, in my opinion, is a very effective treatment for anxiety disorders (GAD, PD), OCD, PTSD, ADD, ADHD and any other disorder that involves negative, intrusive thoughts.

CBT, basically, consists of two parts: Gradual exposure, and a focus on the thoughts (cognition) of a person in anxiety-provoking situations. A subset of gradual exposure is response interruption.

For example, let's say that walking into a crowded shopping mall provokes anxiety (even a panic attack) in you. Well, you have a few options: Avoidance, CBT, anti-anxiety meds (benzo, some SSRIs/SNRIs), or a combo of meds and CBT (or a similar therapy). CBT would, gradually, force you to walk into the crowded shopping mall. CBT would force you to focus on your thoughts if you start to get anxiety. Negative thoughts will be "reality checked" and positive thoughts will occur.

I am NOT a psychologist, so do not use this post in lieu of professional advice. However, I am a person with diagnoses of GAD, PD, PTSD, and schizophrenia.

CBT has greatly reduced my anxiety disorders, PTSD, and has even helped with schizophrenia (along with a med).

I hope this helps.