Based on your current income, you will need $3.8M to retire.

http://blog.wenxuecity.com/myblog/72332/201709/23374.html

Current income $300k

Retirement expense = $300k x 0.75 = $225k

SS income @66 = $36k x 2 = $72k

Income generated from asset = $225k - $72k = $153k

Asset needed to generate $153k = $3.825M x 0.04 = $153k

You are not too far, just double your asset.  You will be there.