Yes, the bank can take a lien against any new property that you acquire. So perhaps you can have the house title to your son with a life estate over to you, just in case your son dies before you.
There are also some fairly simple trust options that could keep your creditors from attaching the new property. You will need to have an attorney for these matters, but it should not cost much. Most attorneys will quote fees in writing before doing the work. The cost should be very affordable. Good luck.
This answer is not intended to create an attorney-client relationship and may not be relied upon as legal advice. A careful examination of the facts is necessary before a legal answer may be relied on. You should consult your own attorney before taking or refraining from any legal action.