In one published in the journal Thyroid, women who had TPO antibodies above 121IU/mL had significantly more symptoms than in the other group. Symptoms including chronic fatigue, dry hair, chronic irritability, chronic nervousness, a history of breast cancer and early miscarriage, and lower quality of life. All women in the study were euthroid (normal thyroid function).
Many studies have shown selenium (200mcg daily used in the studies) lower TPO antibody levels. Results depend on the individual.
It's not unusual for symptoms to show up before labs actually show a problem AND your doctor is looking only at the TSH, which is a pituitary hormone and does not give a clear picture of the entire situation, even though many doctors think it does.
Many of us find that FT3 has to be in the upper 1/3 of it's range, and FT4, at least mid range in order to feel well.
The high antibody count indicates that you have Hashimoto's Thyroiditis, which is an autoimmune disease, in which the body sees the thyroid as foreign and produces antibodies to destroy it. As the destruction progresses, the thyroid makes less and less thyroid hormones, and your symptoms will get worse. You should also get another antibody test, Thyroglobulin Antibodies (TGab), which will also diagnose Hashimoto's, since some people have only TPOab, others have only TGab and still others have both.
It's not the antibodies that cause your symptoms; it's the resulting hypothyroidism, when your thyroid doesn't produce enough hormones. While your levels are still "normal", they aren't optimal for you.
The first suggestion I'd make is find a different doctor. A good thyroid doctor will treat you clinically, to alleviate symptoms, by adjusting FT3 and FT4 to what's best for you.
Because of your symptoms and normal thyroid levels, I'd also suggest that you get Vitamin B12, D, magnesium, selenium and calcium tested, since deficiency in any one of those vitamins/minerals mimic hypothyroidism.