TSH level prior to RAI

I am scheduled to have my first RAI treatment on the 26th of this month. I was told my TSH level would need to be at least 50 in order for it to be effective. I just received my blood test results yesterday, and I am actually at 155! I was just curious to know if anyone else ever got this high and if I should be concerned about my body shutting down, etc. I am feeling tired, emotional, etc. but nothing too bad. Any insight you could provide would be helpful!! Thanks!