I cannot determine your diagnosis with certainty based on a short letter but some of your symptoms are consistent with schizotypal personality disorder. These specific symptoms include:
- consistent, long-term and excessive social anxiety
- preference to be alone
- difficulty with social interaction
- lack of close friends
- suspiciousness and paranoia
To gain the most accurate diagnosis, you should make an appointment with a mental health professional for a psychiatric evaluation. A psychiatric evaluation generally involves a one to two hour meeting with a mental health professional who gathers detailed information about your current symptoms, your historical symptoms, your family life, how you relate to others, your education and career history, your family involvement, and your developmental and medical history. On some occasions, evaluators will suggest blood work or X-rays to rule out any underlying medical conditions.
Counseling could also benefit you. It is important to recognize that for you therapy may be challenging, due to your social anxiety, but it should not stop you from beginning. Based on your letter, it seems as though this is a long-standing issue that has significantly impacted the quality of your life. Though therapy might be difficult, it is certainly worth the effort. It can help you deal with your intense anxiety. Therapy can also teach you the necessary coping skills to deal with everyday life problems.
Medication might also be helpful. Antidepressant medication and anti-anxiety medication may bring you significant relief.
You can look for psychotherapist by clicking on the “find help” tab at the top of this page. You may also want to consult your doctor regarding this matter. He or she may have a referral they can offer for a psychotherapist or may know of a clinic where you can get a thorough and complete psychiatric evaluation. I hope that this answer helps to point you in the right direction. I wish you the best of luck. Please take care.