Maduro’s claim is a fallacious equivocation
robs us of 30 billion dollars and offers us four crumbs
Maduro’s statement is misleading because he’s referring to an “us” that is actually two different groups of people within the same country. The people being “robbed” of $30 billion are the people who run the state owned oil company. The people being given the “four crumbs” are people who are starving to death due to the government’s bad policies and likely wouldn’t receive any share of the $30 billion except in the most indirect ways at best.
It may be true that the sanctions cost Maduro’s regime $30 billion. It may be true that the US food aid is less than $30 billion dollars worth of food. It is not true that these policies are affecting an identical set of people.
EDIT: This answer has been flagged as requiring more sources. I think this is silly because my answer is a demonstration that a logical fallacy is being employed. But, whatever, I will oblige anyway.
Here is a list of current sanctions against Venezuela from the state department, which shows that the sanctions are directed against the state run petroleum company and specific individuals in the Maduro regime: https://www.state.gov/e/eb/tfs/spi/venezuela/
In 2017, the Agricultural sector was 4.4% of Venezuela's GDP. The latest figure for nominal GDP is 96.2 billion dollars from 2018. These values are from this Wikipedia page: https://en.m.wikipedia.org/wiki/Economy_of_Venezuela
If we assume that agriculture and GDP haven't changed much since these figures were released, the total Venezuelan domestic agricultural economy is about $3.84 billion. The same wikipedia page lists total imports for 2017 as $9.1 billion. If we assume 100% of that is food (which it isn't) that puts a ceiling of $13 billion on the amount of money Venezuela spends on food.
$13 billion is less than $30 billion. If we assume that Maduro's claim of sanctions costing Venezuela $30 billion is correct, then there is a minimum of $17 billion that would not be spent on feeding people. This minimum would assume that the Venezuelan government would completely shut down the agricultural sector of their economy in response to sanctions, which is an absurd assumption.
The people who are losing the money due to sanctions and the people who are not able to eat and are getting food aid are not the same people, because the money from sanctions is largely not being spent on food.