May I suggest praying to God and asking for protection of anything that might be looking at you which makes you feel uncomfortable,most of those is all in our heads,so try to relax and calm down and I assure you that nothing is watching you.
before you do any banishing spells or protective spells that drive off spirits, try to figure out if it really is in your head or (if it is a spirit) to figure out if it's intentions are harmful or not.
First off, have you looked into and thought out whether this feeling is in your head? Have you seen shadows out of the corner of your eyes, smelt anything out of place, heard any oddities that were unexplained? I ask this because often times spirits or entities not attached to the physical plane can often work through the olfactory senses.
Now if you have confirmed this I suggest asking said entity what it wants and meditating and opening up your mind for response. Now it more than likely won't be words you hear in your head it'll be a feeling or something along those lines. If whatever happens in the following moments feels good then, leave it be it is a nice entity :D.
If not, then I suggest asking it to leave, if it doesn't then do a cleansing and if that doesn't work. Do a banishing. That should do it.