I am 24 year old ,unmarried . Recently I was diagnosed with hypothyroidism ( TSH : 9 ). My main concern started 2 months ago when I started noticing the difference in my breasts. My left breast has become heavy and larger in size then the right one and also both breasts are tender to touch every time. I went to a gynecologist , she examined my breast and other symptoms like hair growth in neck and heavy abdomen as well.She suspected PCOS and said that although my left breast is larger in size but my breasts looks ok no lump or mass are detected.

She said that asymmetry in breasts are normal. But
I am really worried.This asymmetry is recent and my breasts were symmetric 2 months ago. What should I do? Please let me know what can be the causes of difference in size of breasts and tenderness