What is the difference between 'get over my head' and 'get in over my head'? Which one to use when we are struggling to forget someone?
Get over my head is either a literal spatial instruction, as in
or figurative usage meaning to recover, usually with head as an attributive noun:
It will takes months of rehab therapy to get over my head [injury].
To get in over my head means to find myself in a situation that is too difficult for me to handle. The allusion is to swimming in waters too deep for my swimming abilities:
But the phrase needn't refer to water. You can also drown in debt, among other things.