It would be the best to contact Chinese authorities to inquire about the reason. Even if the cancellation is political, contacting them would not cause you a higher risk than your unclear legal situation at the moment, and such contact may be necessary to obtain evidences that can justify any claim of protection.
If you have frequently travelled to certain countries in South East Asia for unclear private purposes (documented studies and employments aside), and your place of origin is considered high risk (e.g. Fujian), you may have simply been victim of the rather dystopian automated high-risk individual detection system to combat (at least supposedly) the extremely widespread telecommunication fraud. Risk factors includes young age, previously unemployed or employed in low paid jobs, large or numerous financial transactions for unclear reasons, lack of education, record of unpaid debts, or from a village with a disproportionate number of foreign telecom fraud suspects.
If this is the reason and you return, you must be prepared to provide documentation and explanation for all your travels to be eligible for a passport again.
A non essential travel ban is in place at the moment so if you return you will not be able to exit for tourism for some period of time, even if you obtain a passport.
Based on the comments you made, I do not think the tweet being the reason for cancellation is probable. Twitter is unlikely to cooperate with the Chinese authorities and China is unlikely to investigate with that much resources into such a tweet which there are tens of thousands of such messages on Twitter.
But of course, no matter what other reason it may be, the situation sucks for you. There likely is unfortunately no good solutions for you.
Asylum may be an option like other answers and comments have suggested. But I must bring to your attention that:
Malaysia is not a signatory to the Refugee Convention and does not have a definite comprehensive domestic law dealing with refugees.
As such, you will not obtain an internationally recognized Convention refugee travel document. A travel permit may be issued on a case-by-case by Malaysian authorities, and it is not guaranteed to be accepted by all countries.
For the same reason, you have no legal status in Malaysia, even if Malaysia out of good will follows in general the principle of non-refoulment and allows the operation of the UN Refugee Agency. Working is not legally authorized, even if occasional "under-the-table" small jobs are tolerated.
Asylum seekers who return to China are likely to have consequences more serious than for a rude tweet, and it creates even more difficulty for obtaining a passport in the future.