My tsh, ft3 & ft4 levels have increased significantly over the past 6 weeks, following a 50mcg increase in my thyroxine dose. what does this mean?

Recheck the labs: Based on your question, this does not make sense. An increase in your thyroid dose should increase the T3 (liothyronine) and t4, and decrease the tsh. Was there a lab error? Are you taking the meds correctly? Is there something else going on with your thyroid? Are you in recovery from a severe illness? Check with your doctor.