Starting issues

It wont start when the dew point is high, so I changed the distributor cap and rotor and it started that day, but the following day it wouldn't start again. I have also noticed I am getting fuel in my engine oil, it has been changed twice in the past 2 months because it's foamy. The shop changed it the second time and said there is definitely gas in the oil. I fear I have major issues but can't put a finger on it. I know it has spark and fuel but I'm lost.I also noticed after I changed the distributor cap and rotor button it started like I said earlier but when I drove it, it felt like it was missing when driving in normal conditions and especially when I pull a hill. Something really strange going on. It didn't start yesterday but could start today, it's hit or miss. I don't have any check engine lights on either. Please help.