Welcome to our forum alittlebird.
You will be o.k. for two days without levo as it is long-lasting. Get your prescip tomorrow.
It is a relief when you find out you are not the only one to be struggling with hypothyroidism. Many of our members will respond to questions you may ask as we've all had different experiences but most of all, still complain of symptoms even though the doctor might pronounce 'normal' as regards blood tests but is willing to prescribe other medications for the symptoms but not a decent dose of thyroid hormones.
We have to read and learn and 2 years is long enough for you to know you are still struggling.
If you've not had a recent blood test ask for a new one as you have clinical symptoms. Ask for a Full Thyroid Function Test which includes more than the TSH. T4, T3, Free T4, Free T3, as well as Vitamin B12, Vit D, iron, ferritin and folate.
If your GP queries say you've had advice from the NHS Choices Thyroiduk.org.uk and want to recover your health.The procedure is to have the earliest blood test possible and don't eat before it, you can drink water.
Allow 24 hours approx between last dose of levo and the test and take it afterwards. If you take hormones before it will skew results.
Get a print-out, with the ranges (these are important as labs differ) and post on a new question for comments.