Could be OCD, or it could be GAD (General Anxiety Disorder) which is classified as an OCD Spectrum Disorder. This basically means that it is related to OCD, and shares symptoms of OCD, but isn't OCD proper. GAD falls into a category of when you find yourself worrying all the time about almost everything, not one or two specific issues. While OCDers may have extra symptoms, they are usually focused on particular thing (counting, hurting someone, etc.) But, both are anxiety disorders. Many of the anxiety disorders can meld into one another as well which can make a specific diagnosis a challenge.
The fact that you research everyday is not necessarily a bad thing. If you are an intelligent and inquisitive person, it's only normal to seek out information to something you find interesting or catches your curiosity. If you choose to do this instead of completing other tasks, or going out with friends, etc. then it may be something of concern. Checking for symptoms is a broad statement. If you are checking for symptoms to see if you have them but have never experienced a symptom, and then manifest it in your mind, again that is something of concern. If you have had a rash, for example, for a few days and can't explain it (such as cleaning chemicals, or touched a stove, or a rug burn, etc.), it is normal to check to see if it is something serious. Natural hair washing is not anything to be concerned about either. There is a big market for that type of consumer, and not at all a bad idea to limit exposure to chemicals, especially if you are hyper sensitive to them.
Hair can fall out from medications, hormone changes/imbalances, and stress, including anxiety. Anxiety and stress tax the nervous system which, when beaten down, drains the body of energy. The body dips into reserves (fats and protein which is fat and muscle) to find and use energy sources. So when you are stressed and don't eat from anxiety, that is why you see many people lose weight. Plus, the effect it has on the gastrointestinal system making it difficult to keep food in the digestive tract robs your body of needed nutrients. Protein is needed to rebuild hair and strengthen the follicle for new hairs to regenerate. Any major disruption can cause the hair to go dormant and fall out. If you constantly tug or pull at the hair strands, this can put undo stress on the hairs also.
Now, for the intrusive thoughts it depends on: what they are; how long they take up your time; how you respond to them, etc. Everyone has intrusive thoughts. It's the makeup of our brain. The difference between the "normal" people and the anxiety people is that the "normal" people tend to slough it off and not give it a second thought. The anxiety people get it locked-up in the thought process wondering why it came about and did they purposefully think it. The answer is, no. They didn't. Our brain is complex. It processes billions of information constantly even withut us knowing it.
While you are reading this, it is processing these words, telling your eyes when and where to move and focus, telling your heart to beat and your lungs to breath, telling you to shift in your seat when the body gets uncomfortable. It is constantly active, even when you are asleep. This is why we dream. And why sleep is important. It is the time the brain defrags (like a computer), arranges files (memories and information), recharges important cells and neurons among other things. And, we have nightmares which are the minds inability to reason or comprehend certain information or input. When we are stressed, everyone has similar nightmares: drowning, caught in a tornado, falling, flying, etc. Did you think of the nightmares? No. You didn't even plan on them to happen. But, upon waking we all dismiss them as only nightmares and accept the fact that it was out of our control.
These intrusive thoughts are the same thing, only you are awake and aware. So, you misinterpret them as being your own thoughts. However, they aren't. Its your deeper, "subconscious" brain being during the day. And, when anxiety people have these thoughts it creates more anxiety because the awake, alert brain (basically you) cannot process from where these thoughts are coming or why you are having them.
And in your desperate attempt to find those answers you begin searching, reading, looking. Again a natural response; however, the cruel twist of fate with anxiety is there are no concrete definitive answers to why, or when, or how. They just are. And they always will be. It's up to the individual person whether he/she chooses to fall prey to it or overcome it. Yet, this is still a challenging journey because the anxiety mind is still active responsive to more questions; especially the unanswerable kind. It's like trying to comprehend why the stars are there, or the moon, or the earth rotates. With these you eventually accept someone else's answer, or you find it of no interest or concern so you lose interest and move on. However, when it comes to concerns about us or those close to us, we search for certainty and a solid foundation of thought and reason. But, like the contemplating the stars, there are no answers that can make you 100% sure.
Long response, but hope it may have helped in lessening your worry.
Good luck!