Hi Leroy, welcome!
As spynappels has already said the fluctuations in difficulty are caused mainly by the short-sighted coin jumpers who use sites like coinchoose and coinwarz to choose the profitable ‘coin of the moment’ to mine. Once they’ve mined it to the point where the difficulty rises past their short-term profitablity window - they jump to the next coin and the difficulty goes down again.
The more solid long term miners we have the less of an issue that will be.
TN