Electrical Problems

I am experiencing a handful of electrical problems with my car. A while back the blinkers slowly stopped working as it used to be one to ten times starting the car they did not work to every two to five until they stopped all together. Along with those the A/C/heat system and reverse lights no longer work. Now the radio and power windows are going through what the blinkers did. Most of the time starting the car they work but they slowly are not working together. On a separate note (this is probably electrical too) but the car will not stay running. The car was plagued with a low idle for a very long time and now it starts and immediately dies. I figured out that for it to stay running you have to start the car, but hold the key in the start position (the most forward it will go) and it runs. If you let go of the key, it shuts off. All the fuses look good and none of this was a problem a year ago. Not sure where the issue is. Thanks! Sam