It did drive me crazy, so crazy I ruined the meat. Ugh I really think my grill thermometers are off, something is wrong I will try to get to the bottom of it next cook.
Ruined? Hmm, how bad? I can almost always come up wth a salvage if something gets overcooked/dried out...a leftovers dish maybe?
You may need to check the calibration of your thermometers. I try to check mine about once each month in a water pot. I bring the temp up from cold over a medium/high burner temp with all of my thermometers suspended in a grate resting over the pot to prevent any thermometers from becoming submerged. As the water temp rises, I can watch the rise in temp readings on each of the digi-probes and/or analog thermometers. I've never had a digital be off more than 1 - 2* F, but analogs are very suseptable to vibrations, shocks (dropping), bent stems etc.
Most analogs can be calibrated (small nut on the base of the stem can be turned with a wrench to change the reading) while digitals are not...you just have to note if they are off, how much and which direction (+/-). I bring the water all the way to a slow boil, which is about 12-15* below a full rolling boil, check all therms again, and then take it to a full boil for the final check.
When I remove the pot from heat, I recheck the readings about every 5-6 minutes as the water cools down to see if they are all reading close to the same temp. This can help to determine if any analog thermometers have a hanging/sticking needle from a bent stem or other damage.
Heres a link to a water boiling point chart based on elevation/barometric pressure. Water boils @ 212*F @ sea level (rapid boil), but temps drop as barometric pressure/elevation drops.
Keep on trying, 'cause you're getting closer to easy-street with every fire you build. It sounds like you're just going through the standard issues that most of us deal with every time we start dialing in a smoker...it'll come together soon. Starting out fresh to smoking meats makes everything that doesn't go quite right seem to be overwhelming, but being new to the craft amplifies everthing by about 100-fold...that includes your successes, btw, so don't ever feel like your getting excited for no reason when everything comes together. The excitement of cranking out something great to eat keeps me coming back to the thin blue smoke every time. Every smoke will present you with some learning experiences...that's why I love it so much. When in doubt about whether or not you should continue, just think about how good your dinner will taste when it hits your plate...LOL!!!!!!