DRU300CE

Hay anyone please i need help! I own a 1993 300ce coupe. Awhile after i bought her she started running tarrible. took her in to machanic and had her scoped. Came back to me with 2 out of 3 coil packs were bad, needed plugs and the wires were origanl. I replaced all the plugs and wires and addmittedly replaced the coilpacks with some that werent the best.after that she was running better but not like she was before the innital incodent. rough idle, and low around 5 or 600rpms and jumpy.
i replaced some wiring under the hood that was old and brittle. then about 30 days or so after replacing the coil packs they went out again. This time i replaced them with Bosch. but even still the rough idle still presists. i've stopped driving it all together now as a few days ago the coil packs stopped working so i turned it off. when i went out and started it again they would work again but after driving for awhile id loose power again. it may not be the coil packs but feels like the same symptoms.
i started looking at other possabilities and saw that the camshaft position sensor had a crack in it. after removing it i also saw it had oil on it. before i order another part that might not fix the problems im having can anyone give me some advice please?