My struggles with Depression/Agoraphobia/Anxiety

Hello. This is my first post. I am 18 years old, I have been suffering from Agoraphobia and depression since I was 15 years old, it started when I was in high school, It started out with panic attacks and mild depression and quickly developed into agorophobia. My doctor put me on antidepressants at 15 (at the time I didn't know what they were)I stopped attending school at 15 an with the help of the school i was given a tutor for an hour three times a week. I failed at my exams because of this.
When I reached 16 years old I became completely housebound, leaving only for the doctors. I stopped taking my medication as i simply didn't go to the doctors. I sleep odd hours, I have done since I started with this, I am usually awake at night and asleep in the day because of my anxiety. I feel more comfertable in the night. I have tried sorting my sleeping patterns out but they just go back.
When I was 17 I started recieving benifits. I have no friends anymore (So called, can't even be asked to give the occasional phone call).
I have tried to commit suicide three times.
I spent almost a year shut in my bedroom with the curtains closed, the only time i would come out was to eat or watch telly, sometimes I couldn't even do that because i felt like people were watching me or judging me through the curtains ( i know it sounds silly)
Sometimes when my depression is at it's worse I shake and curl up on the ground crying. I now find myself at 18, with no job & housebound. I can barely answer the telephone without panicking. When people come to the door I usually hide in another room or go upstairs.
My mum has depression also, In 03 she had a major stroke...she supports me completely with it, but she cannot do a lot, yet shes there doing the shopping every week because I can't. I feel awful because I can't do this. The only time I will leave the house is with her or another family member. I am a very heavy smoker also.
I feel hopeless every day. I went back to the doctor around 8 months ago, an he put me back on meds, I stopped taking them and ended up more depressed than I was. When I had a mental evaluation at 16, the woman told me I should attend Anger management and an anxiety course. I don't have anger problems. My doctor doesn't seem to know what to do. I have signed up to a depression course. That was 2 months ago and haven't heard from them since. I wanted to attend an anxiety course. But I cannot attend without a letter from my doctor. Go figure.
I find myself every day getting worse. At 18 I am like this..what the hell will i be like at 20? I feel like the world would be better off without me.
I want to get my life together but I don't even know where to start? When I tell people they say well do something about it but how?
I long to be like everyone else. I just want to cry all the time. No one seems to give a sh** either way.
I just don't know what to do anymore

Hello Anxiousboi23

Could you see another doctor at the surgery or change to another practice? It sounds like it might be worth trying someone else. You seem so depressed I think you do need the medication, but a referral to the mental health team would probably be a good idea too. I was very depressed earlier this year, but did find the anti-depressants (Sertraline) helped me a lot. If I were you I would keep going back to the doc until you get something more than just another prescription. Have they never suggested counselling?

Life can and does get better. I hated my teenage years, I much prefer being older and things did work out better for me in the end, even though I still have anxiety. Hang on in there and try and get some professional help.

Tyke