I'm 20 years old dealing with hypo thyroid i weigh 136 am i overweight i am 4"11 in height.. i also do not get normal periods.

Both are expected: Both the hypothyroidism (untreated) and obesity can delay or eliminate menstrual periods. Once the hypothyroidism is properly treated and the thyroid function returns to a normal state, then you can work on the elevated BMI and lose weight. It may take several months in a "normal" state before normal periods resume. Work with your MD closely on both issues.