someone help? 😞

So last week my son went in his cot, sometimes okay sometimes not, 3 nights since last week I've had to put his Moses basket in his cot because he won't go to sleep unless he's being rocked (which I stupidly started a few weeks ago) how can I get him out of this and start sleeping in his cot, he will cry and cry and cry until I start rocking him and i don't want to resort to that anymore 😓