I am no medical doctor, but 160 total cholesterol seems to be a bit on the low side. Low cholesterol for women is associated with higher mortality (ref. Norwegian HUNT study following over 50,000 people over 12 years).
Cholesterol tests are also not the most accurate. They can vary from day to day and from lab to lab.
That being said, if you have been low or lowish carb Paleo, the cholesterol increase is a possible (red) flag that should be investigated further, especially since you are hypothyroid. Paul Jaminet has some excellent posts on his blog that you should check out:
The glycogen content of the liver affects the conversion of T4 to T3 in the liver (where cholesterol is also involved). If you do not have enough glycogen to produce (enough) T3, the cholesterol will go up.
If you are on T4 meds instead of natural thyroid, you may be even more at risk, as the T4 only meds assume that you are able to convert T4 to T3 in the liver.
You might also want to check out this PHD article:
Anyway, 220 is not terribly high, but you might want to check your free T3.