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:
In his response to your question, Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
If, because of your specific circumstances, you find it hard to fast these long hours to the extent that you fear fainting, then you are allowed to skip the fast.
However, you ought to make up for it later; you may do so when day hours are shorter (in winter).
Allah Almighty knows best.