Low vitamin D common when hypo and linked to poor sleep.
Post your latest thyroid results, including ranges. Plus if you have them, tests of vitamin D, folate, B12 & ferritin. Common for these to be low & if these have not been done ask GP to do so.
As greygoose says, 25mcg is a starter dose. We should have follow up tests 6-8 weeks after each dose change, and Levo increased in small 25mcg steps until TSH is at lower end of range and symptoms have improved
Thyroid blood tests should be done as early in morning as possible, fasting (drink plenty of water to keep hydrated) and don't take your Levo in 24 hours prior to a test, take it straight after. This way TSH is at its highest, which is all most GP's consider for dose levels.
Like marsaday I also find taking Levo at bedtime much more effective. Recent research backs this up, but some try it, and don't get on with it. We are all different.