1998 Chevy Blazer runs when it want

Truck started to run rough. Check engine light came on codes read, #1 cylinder one misfire, #2 multiple cylinder misfire dectected. I put about 100 miles on it parked it for the night. The next day went to start and after about 4-5 time cranking it over it started. I drove it to the store about 1 mile total then parked it. About 10 mins later I went to leave again and it would not start. So I changed all six spark plugs which took me about 2 days due to other obligations. After changing the sparks it still took a couple trys to get it started (note: check engine light turned off and engine was runing smooth). I drove it to the store filled it with gas. Parked it for about 4-5 hours. After about two trys it started again I let it run for about 10 mins then turned it off (note: this is at 3am when its about 50 degrees I was geting ready for work and figured I would test the truck again) turned it off. Let it sit for about 12 hours and now it wont start again at all. I know its getting fuel because I checked on the out flow side of the filter. What should I do now? I need this back on the road asap. And would like to do it as cheep as possible. Please help thank you