Thyroid hormone replacement meds will ALLOW you to lose weight. When thyroid hormone levels are off, it's almost impossible to lose weight. Once your hormones are properly adjust with meds, you should have a much easier time. Notice that I said once they are properly adjusted, NOT once you start. Adjustment is a trial and error process to some extent. The dose we are initially put on is seldom the dose we end up on, so it can take a while to get it right. It takes some patience and labs should be monitored every 4-5 weeks during the adjustment period.
Do you have actual lab results to post? If so, please include reference ranges which vary lab to lab and have to come from your own lab report. It's a really good idea to get a copy of every lab report for your records. By jotting down symptoms and dosage before each blood draw, you can start establishing your own personal history.
It's not hopeless...you just have to get those hormones to roper levels.