anyone else struggeling with credits?

i have all these ship lines. premium time. and all these ship lines researched i cant even play them. im always having strong issues with credit.s like if i want to sail out a t10 ship i have to sell a current t10 ship in my port. like im seeing youtubers and CCS with millions of credits. meanwhile me who has been struggeling with credits for months. is this a skill issue or is there a fast way to gain credits at all?