Hello, sorry but in my opinion your macro is ruined. Indeed, when you record, you overwrite the previous version. there is no backup backup on a macro as far as I know...
Doing a lot of macro, it has already happened to me several times.
I found a way (not great) to solve this problem, it's to simply open it in another version of solidworks and copy the code and export the userforms if there are any.
I had the problem on SW2016 and I opened the macro on SW2013 (Yes it works!) and I was able to recover my code.
It seems to me that by opening it to another workstation it also works.
I had opened a ticket with our reseller for this problem he offered me to uninstall a windows KB which can generate operating problems with SW (2014 SP4, fixed on 2015 and 2016)
@KVuilleumier, depending on the support, it can be a clue about macro recording problems. After if the storage locations are on a "virtualized" network (which is our case) I think that the recording problems can be due to the server refresh during the recording (or micro network loss that Solidworks hates)
Concerning the KB, I couldn't test because it was complicated to get the manipulations done.