What To Do?

So I've been thinking a lot about what is going on inside of me. I have a lot to be grateful for, at least I am told that all of the time. I am going to be a grandmother, my fourth child is graduating from high school and going on to college, I have a mother a husband and a niece who count on me and two children still at home who need me. But does anyone think about what I need? Does anyone consider how I feel when I am told: "You ask too many questions!", "People judge me by the way you look.", and my favorite when I disagree with anyone in the family; "Have you been taking your medication on time? You don't seem to be thinking clearly."
According to my family, I am only exhibiting well behavior when I sit back, nod and smile and let everyone do and say as they please. I am not allowed to disagree or express my feelings. Apparently, my feelings are not real because I am mentally ill. If I were not ill or my medication were working properly, I would see that everyone should do and say as they please. Basically, my feelings are invalid! Nobody seems to understand that my feelings of inadequacy date back to my early childhood and are only compounded by my present family dynamic.
I have been sitting here all evening trying to come up with a reason to continue living. I cannot come up with a good one. I am nothing. I will always be nothing. So... what to do? What to do?
I cannot decide whether to take pills again or stick with my original plan of gassing myself in my car. I am leaning toward the car thing. Here is what would make it perfect:
1. Park by the river in the evening right before sundown.
2. Get out and run a hose from the exhaust into my rear window.
3. Either shoot some heroin or light up a nice joint. I have never done heroin so I'm kinda thinking this might be an opportunity to experience an incredible high before I die.
4. Turn on the radio, The Moody Blues or Pink Floyd.
5. Watch the sun set as I wait for death.

Now... to find the perfect time.

I have been having a rather rough time and haven't had the strength to post. I am so tired of feeling this way. I feel as if everyone is working against me and I am miserable. I am hopeful though. Hopeful that I will be brave enough to finally end all of this.

Maybe My Life Can Help Someone Else

I am not sure where to begin. I am, at this moment; one second away from tears. I am happy, sad, excited, optimistic, hopeful, hopeless, of use, useless, rigid, flexible, brave, fearful, special, and ordinary-- all within a matter of minutes. I am bi-polar. I am writing this because perhaps someone else will read this and maybe, just maybe they will realize they are not alone in this and maybe, just maybe my life will have been worth something.
I am not sure I can live much longer like this. I have been through psychotherapy, hospitalizations, countless medications and electroconvulsive therapy. I keep telling everyone "Oh yes, all of this really works! I feel much better!" I don't want anyone to feel sorry for me, I just wish I could live a full, happy life. I don't feel valuable.
When my children were small, I still had ups and downs, but not as severe as these. They kept me busy and I was the center of their universe and they mine. As they have grown, some of them have left the nest already and those who have remained seem to find nothing but fault with me. I still spend my days doing little else but trying to provide a happy and full-filling childhood for them and a nice life for my husband, what with cooking, the learning, the transporting people to activities, making sure dreams of beautiful prom gowns and special occasions are met. And you know what? It still isn't enough.
I not only hate my life, I am weary.