Answer
Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
1- It is well known that to lie and to cheat is unlawful (haram). So, you should not expose yourself to falling into such sins.
2- You can either convince your parents to increase your budget or seek a part-time job to be sure you are earning your living from a halal (lawful) source.
In his response to your question, Prof. Dr. Monzer Kahf, Professor of Islamic Finance and Economics at Qatar Faculty of Islamic Studies, states:
Lying or cheating is not permissible even to parents. You should know that you are better off than at least 95% of Muslim children whose parents are not able to support their living.
I think you need to convince your parents or at least not lying to them.
You seem to have forgotten the third option which is to find yourself a part time job along with study.
As a husband and a father, it is about time that you earn your living rather than depending on parents.
Allah Almighty knows best.