I Have Been So Tired And Have Had To Stop

I have been so tired and have had to stop on the way home to have a snooze. Not everyday. I am over weight but have normal bp and no diabetes or high cholesterol, I have been tested for thyroid, but only the one test. I hear there are other test that can be done for Thyroid, as I have had a lump in my right side of my neck that needed to be drained 10 years ago. Had antibiotics and it stayed away. I have started to get the lump back but it seems to be something else as it is not growing fast like the other goiter did.. they never found out what caused the last big one that need to be drained. but now that it is happening and I am a little uncomforatable in my right side of my neck. just wondering ....