The speeches you listened to saying poor people will be happy in the next life would obviously be talking about people who meet the minimum criteria to enter paradise to start with (i.e. the people who are Muslim and whose sins Allah forgives).
There's 4 simple possibilities:
i. a poor person can be bad and do shirk and could end up in hell
ii. a poor person can be good and do good things all his life and end up in heaven
iii. a rich person can be bad and do shirk and could end up in hell
iv. a rich person can be good and do good things all his life and end up in heaven
Just because someone is poor, it does not automatically give them free entry into paradise and just because someone is rich it does not make them worthy of hell.
However, there is a hadith which says the poor will be given entry into paradise 500 years earlier than people who are rich.
I don't know how true what you say is but so what if it is, sister?

People can be rich and have what seems like everything in this world and also have it in the next. Secondly, being 'rich' does not mean you are automatically not given any hardship. People are tested in various different ways.