I definitely think there is something important to sort out here. While variations in mood and energy are certainly normal, the extremes you describe and your description of “almost never being in the middle” of the mood scale are definitely suspicious for a possible mood disorder. Bipolar illness is characterized by repeatedly engaging in impulsive behavior with a high probability of negative consequences, bursts of energy in which the person gets very little sleep and is obsessed with the activity, and excessive anger and irritability (and sometimes feelings of grandiosity and euphoria) among other symptoms.
Most people with bipolar illness cycle between highs and lows in mood and behavior and these cycles can occur closer together and happen more frequently as the individual gets older. In addition, initial symptoms of euphoria when in a high energy phase often turn into more irritability and anger and less frequent euphoric feelings over time. In addition, the lows usually start to predominate over the highs with more and more depression happening over time.
Often the person does not realize how extreme their moods and behavior are although it is quite noticeable to family and friends. I would take their feedback seriously and get a professional evaluation to determine whether or not you do have bipolar illness or some other kind of mood disorder. The diagnosis affects the treatment choices and it is important to get the diagnosis right the first time. It is important to note that bipolar depression requires a different form of medical treatment than more common types of depression.
Over time, an unidentified and untreated bipolar illness causes more and more problems in the person’s life with jobs, relationships, health, and money. While it certainly feels scary and possibly shameful to find out you have such an illness, diagnosis and appropriate treatment can restore feelings of well-being and lead to more success in various areas of life functioning.
Bipolar illness can be tricky to identify and treat. Treatment usually consists of a combination of medication and psychotherapy. Being diagnosed with a serious mood disorder isn’t something anyone wants to experience, but given the problems you are having with jobs and family relationships, it is definitely important to check it out. You can read a bit about the illness online and see if the symptoms match your experience, but only a professional can really diagnose and treat the problem.
Be proactive and listen to the others in your life who care about you. Even if it turns out that you do not have bipolar illness, there is help available to assist you with your difficulties with anger and depressed moods. I strongly suggest that you give yourself the opportunity to make your life better.