Is it harmful for you walk on your foot if you have morton's neuroma / metatarsalgia?

Not necessarily: Harmful? Not necessarily. Hurtful? Likely. See a podiatrist for an evaluation and determine need for special footwear, orthotics, medication, injections or surgery or other options. Avoid high impact activities in the meantime, avoid high heels/tight shoes.

Do not suffer: You can continue to walk but try to avoid tight shoes and socks. If conservative treatments are not enough then surgical removal is a good option. Many people walk with less pain even the first day after surgery.

Only if it hurts.: A morton's neuroma is a nerve that is irritated, or inflammed. If you have no pain on walking then don't worry about it. If you do, then you are exacerbating the condition and should seek treatment. Home remedies would include ice and rest. If that doesn't work, it might be time to consult a podiatrist. Further irritation can cause numbness or tingling of toes.