Make an appointment with your doctor right away. This may not be a mental health problem at all. It may be a symptom of a medical issue that needs attention. Start there.
If you aren’t getting at least 7 hours of sleep a night, it may be as simple as sleep deprivation. If that’s the case, put yourself on a routine that will ensure that you are getting quality sleep. That means getting to bed early enough that you will have at least 8 hours in bed. That means putting your phone in another room and getting off all screens at least an hour before bedtime.
If you are doing the basics — eating well, getting some exercise every day and sleeping at least 7 hours a night – and if your doctor determines that you are medically fine, then consider seeing a mental health counselor for an evaluation.
You are wise to ask for help now. This has already gone on too long. Although I do understand your wish that you could handle it yourself, it’s time to get some consultations.
I wish you well.