When we treat hypothyroid we try to achieve a
tsh level at least near 2 before we start reducing the dose any ways. I suggest you start taking thyroxine 75 mcqs 30 mins before your bf. Recheck tsh after a month.
For your
b12 take T. Benformet forte one tablet daily for one month. The rich source of b12 is non veg. If your veg then continue taking this tablet and consult a nutritionist who can give you a proper diet plan, so that in future you will not have any of this deficiencies.
Cap. D - rise 60k one cap in the afternoon, then the next dose after 15 days one cap. The cheapest source of vit d is sunlight so expose yourself to sunlight for 20 mins daily between 8-10 am.
Next Steps
Regarding your
thyroid if things do not work out consult an endocrinologist.