I gave a thumbs up to Bellas answer
as it applies to written contracts.
That said, oral by-the-hour agreements serve residential projects far better
and are by definition easier to terminate by either party for any adverse condition reason, which includes illness.
It still applies that paying for services rendered is apropos & avoids you being a thief
but some services may not directly apply or be controversial, thus negotiated, e.g. you never agreed to outdoor stairs to the second floor & gave no design latitude to seek such a solution OR question a 5 hour site visit when the results might have been gleaned in 2 hours.
In most cases, a letter of copyright release and work to date should be able to be used by others taking this project forward, once all fees are paid in full. Note that all liabilities are also transferred to the next party taking up this baton. You might even be best served by this architect's referral to another, since he/she is an insider and .. opposites attract.