This will be a big change for you and are probably going through something similar to stages of grief: denial, anger, bargaining, depression, acceptance.

Like others have mentioned, it is getting rarer that the next generation feels obligated to help the previous generations. I am single and not a lot of support from siblings as I deal with medical issues; so have accepted the fact that I cannot rely on them as I age. When time comes, I will find housing where I feel safe and help available if needed. Unfortunately as population ages, that type of housing is hard to find or expensive. Some areas have agencies that can help with this process.

You mention you can live independent so you're probably not ready for assisted living but an alternative may be a senior living situation. This would give you more social interactions and people around in case of an emergency. Some senior complexes are income based.

Have you thought of asking your son to assist you in locating housing in a senior community and helping you move before they move? Also, maybe he can help you set up your computer / phone so can do video chats after he moves.

Good luck
Laurie