There are multiple reasons for these symptoms which deserve further investigation. One of the top diagnosis that I would want to exclude in your particular condition would by hypothyroidism
which is an under active thyroid gland. This can be checked with a blood test
called thyroid function tests
where they messure 3 hormones TSH T3 and T4. If your thyroid is under active sometimes further tests are required to discover why. The treatment is often straight forward taking thyroxine
a replacement hormone.