It sounds like you are experiencing depression mixed with some symptoms from having overprotective parents. When you have parents that protect you too much from the outside world, it can leave you without the social skills you need to develop friendships and work relationships. It can also create a feeling that there is something in the world to be protected from and that others are not ok to be around. This may be why you feel like a target and are having trouble feeling like you fit in.
Combine the depression with lack of social support/interaction, and you would feel down and may want to hurt yourself. You may feel there is no choices and therefore no other option.
Lack of motivation and enthusiasm is one of the most difficult of symptoms with depression. It often keeps people from helping themselves and reaching out to others. But support and self help are vital in helping you to overcome depression. Consider support groups, either on line or in person. People who are experiencing the same symptoms as you are can offer invaluable support, ideas and companionship to help you feel better. Also, working on depression at home can supplement therapy or other treatment. Here are resources to help you get started:
Medications are also helpful if you feel you cannot function. Getting your symptoms to a manageable level so you can get treatment to reduce or eliminate your depression and urge to self harm is vital. If you feel you cannot function, then any other treatment options won't help.
Whenever medications are used for treatment, it is very common for people to need to try at least one or two different medications or more before finding one that helps. This is because everyone's body chemistry is different. So if one medication works for one person, it may not work for another or it might even cause adverse side effects. So don't be discouraged. You will find the right medication for you.
You may also want to address your social interactions by learning more about how to engage others and make friends. Here are some resources to help:
The more you can learn about how you feel, the more tools you will have to address the problem.
If you begin to feel overwhelmed by a need to self harm, go to the nearest emergency room to get help. Nothing is worth hurting yourself over.
I hope this has helped you,