No power to the blinkers radio stereo horn the buttons, etc.

I got an electrical problem with the Mercedes. I have recently had problems with no power to the blinkers radio stereo horn the buttons on the steering wheel. Cigarette lighter glove box and sunroof from time to time the boot also goes as well. Which are not able to unlock via the switch I have had to use the actual key it all started with my fob key that had stopped working then went the radio from the radio led to the blinkers, horn, cigarette, glove box light, wipers and sunroof please know that I have changed the SAM module along with that the fuse as well as the turn signal switch assembly and then all light bulbs and yet this no power to it all even with all that not working anymore. Since it has all happened I am still trying to figure it out of how I am able to fix it as I have already spent $2,500.00 that I am very upset losing that much. But I love this car Mercedes Benz is from my childhood from when my father had one when I was growing up. I just love them just not this issues that has been here for last few weeks now. Please if anyone can help I would appreciate it very much too.

Thank you kindly, Mr. Johnston