Hi D, (hope this ok to call you D)

 After reading your post several things jump out at me and a few suggestions for help come to mind. I always take everything at face value and treat every situation with serious consideration because regardless of the origin of any given situation, a person is in pain and is asking for help. A few questions first though...

Did you begin studying demonology before or after these events started? It would be helpful to see where your mindset was before this began to occur and how life was in general. Often times, these things can find a way into your life when you have been particularly sad or angry and fuel circumstances to build on that situation.

My next question is are you nearing middle age? I know it sounds crazy but it is relevant as our hormones begin to change around this time frame and can cause problems. What some people might call 'mid-life crisis'. Not that I think you are experiencing one, but hormonal changes can make you an easy target if you are having trouble coping.

Do you drink or take any substances that impair your state of mind? If so, stop. These make you more open and easier to manipulate.

Final question, are you religious and if so, what is your preferred religion? If you are not religious, what religion are you most comfortable with? You may need assistance that cannot be provided on this board. Typically in the form of a house blessing or cleansing.

Now onto the hard truths that no one likes to talk about. See a doctor. No seriously, go talk to a doctor and explain that you are having anger issues and then listen to the options that are available to you. I say this because spirits and demons are not the root of a problem, they take a problem that is already there and they build on it. They feed it until they can manipulate it to get the effect they want.
Even if you rid yourself of whatever entity is troubling you, you will still have a lot of emotional aftermath to clean up and dealing with things now will make it easier for you to take back your power.

So, dealing with a demon is not unlike dealing with most spirits you'll just have to be more vigilant as these guys really like to implant themselves in your life to the point where you don't know where they end and you begin, so start with you.

Who were you before this started? You're really going to have to learn which thoughts are yours and which ones aren't. If a thought or statement seems out of character then it probably is and you should spend more time thinking about it before acting on it. A doctor can suggest ways to help you manage your emotions and that is very important if you want to be in control of your life.

Next hit up your local church for holy water. Catholics usually have a pedestal near the door with some in. You don't need a lot, just a small bottle will do. While you are there dip a finger and cross yourself for protection. (Middle of forehead, center of chest, right shoulder, left shoulder)

When you get home, clean the house, top to bottom. Basement to attic and leave nothing untouched. If you can use lemons or a cleaner with lemon oil all the better. While you are doing this open every window and door, every curtain and blind. You want as much sunlight in the home as you can and you want to replace any burned out bulbs and place light in any dark spots.
Negative entities thrive in dark unused places. Don't give them one.

When you finish cleansing, you should burn sage throughout the house and if you lean a bit towards the occult side of things then you should also cleanse it with water (tap water is fine), earth (salt), and fire (a lit white candle) from room to room. You can pray or say a small blessing as you move from space to space. You can find many prayers online or say whatever feels right to at the time.

Next I would strongly, strongly recommend performing the Lesser Banishing Ritual of the Pentagram or LBRP. This is a banishing ritual which invokes God and the Archangels to cleanse the area. You should do this in every part of the house. You should do it for yourself daily. I also recommend the Rose Cross ritual for yourself daily.

Once you've cleansed the house use the holy water to draw crosses on every door and window. I would also salt the windows and doors until you are certain the situation is resolved.

I recommend carrying smokey quartz and hematite with you at all times. This will help you stay grounded. If you feel anger hold onto the smokey quartz and channel all of those feelings and thoughts into the stone, then take it outside and leave it on the ground over night away from your doors and windows.

If these are unsuccessful for you then you will need to talk to a spiritual advisor you are comfortable with about the situation and ask for a blessing. (If you say exorcism they will disregard anything you have to say). My advice there is to look for one that really cares about what they are doing, one that these rituals mean something to. I can read a prayer from the bible all day but it will be meaningless unless I truly believe in its power to bless and protect a home and its inhabitants.

I know, long post so quick breakdown:

1) See a doctor and get your anger under control. It's natural to want to protect people and help, but hatred and violence is not a place to dwell. It will only bring you trouble. Don't get me wrong, I don't believe in the "be happy all the time and if you are not fake it until you are" ideology. We are human, we have a full range of emotions and they all have their place in our lives, but none of them should have power over our minds.

2) Go to church, get the holy water - long established traditions and rituals chalk full of ingrained belief over thousands of years ain't something to ignore when you need help. There is power in it, even if you are not Christian because western society has subconsciously trained us that holy water is... holy.

3) Clean the house, do the rituals. You can find the LBRP and Rose Cross online in many variations if you prefer not to invoke angels. If you are ok with angels in general start praying to the archangel Michael. He is the protector you will want.

And finally, don't half ass any of this. Once you start see it through to the end.

 Best Wishes,
 LJ