Ok thanks for your reply.
Based on your replies, there are few possibilities:
1. Inflammatory myopathies--- inflammation of muscles from autoimmune conditions ( lupus, RA, polymyositis etc.)
2. Metabolic storage disorders
3. Hypokalemic periodic paralysis
4. Neuromuscular diseases like myesthenia gravis, demyelinating neuropathies.
5. Endocrine disorder like thyroid disorder, diabetes, vitamin B12 deficiency etc.
Hence, you should see your doctor soon for thorough evaluation.
The treatment depends on the correct diagnosis.
In the meantime, physical therapy to strengthen your muscles & gait training may be helpful.