well self confidence is important when working with spells and magick, so you might want to go on a inward journey to build your inner strength.
you could try talking to the entity if it is a spiritual being, it could be friendly and wanting to help. look into pendulum work if you have trouble communicating with spirits [you can also always try meditating and asking questions.]
the other option is it's a build up of negative energy that has manifested as a type of thought-form. if this is the case you cut off the energy flow and this would stop the entity.
in either case i suggest a cleansing and protection of yourself and your home. [this may require multiple castings if you have a large build up. it is a good idea to do regular cleansings and protections throughout the year because negative energy can get stuck to us in our daily lives and build up over time] there are many methods so find one that works best for you. easy personal cleansing is to have a sea salt bath or shower, visualize tar stuck to your body, and as the water washes over your body, the tar is being removed and sent down the drain with the water [a chant i use is 'stress and strain go down the drain'] you can cleanse your house with sea salt water in a spray bottle [sage smudge is a common one too, but if you can't find it, you still have many methods to choose form] as your sprinkle the water around your home, again, visualize tar stuck around your home, and as the water lands on the area it turns into white light [or smoke, or evaporates, or whatever you want to visualize as long as you visualize it leaving to be replaced by positive energy] again, there are many chants you could use if you so desire, or make one up [i usually ramble my way through lol, but the main thing i repeat is 'all negative energy begone from this space' then when i'm finished my whole house i say 'by my will this space is now purified']
once you've cleansed, you should protect so the energy doesn't rush right back in. for yourself you could wear a protection symbol, or say a chant, or carry an amulet/charm with you [again, your choice] for your home, you can say a chant, hang up a charm/symbol to protect the place [if you live in a house you could sprinkle salt around the building or a loose leaf protection incense] personally, i have protection oil i anoint the doors and windows with.
but with any cleansing and protection, you need to be confident and know it worked. do not doubt yourself, it seems easy, but it works. don't assume one bad thing equals the cleansing/protection failed. [since you are good with sensing energy, you should feel a difference, lighter, happier, calmer are common things to feel] good luck to you.