Pinyin is leading me to trying to pronounce things too much like English where the sounds are sometimes not that similar. :-/

part of the reason is this wasn't a problem for their target audience. what really helped me with this problem was going through the chart of all the chinese phonemes and practicing the pronunication as standard as possible. you've got to disconnect it from the English pronunciations

something like this: https://chinese.yabla.com/chinese-pinyin-chart.php