Saw your previous post on this. I suspect the lack of replies there reflect that it’s impossible for any anaesthetist online to say anything terribly helpful. It also sounds like the people looking after you have also told you that the tumour and epidural are unrelated from reading your second post here.
An epidural cannot have caused a tumour to appear in 6 days. What is most likely is that you had the tumour but with no symptoms and either the process/position of pregnancy/labour has made things worse or the epidural may have irritated things (but that would obviously only be an issue if the epidural was sited at the same level as the tumour). The epidural may not have given decent pain relief because a large tumour could conceivably distort the anatomy and stop the epidural anaesthetic spreading.
It may be that if they’d known you had a spinal tumour they’d have not sited the epidural (because it would be less likely to work and because it inevitably causes confusion about cause/effect if there are symptoms afterwards), but it sounds like you were asymptomatic then so there would have been now way to know.
Epidurals can (rarely) cause nerve injuries, as would have been mentioned during the consent process. Presumably if you’ve got as far as having an MRI then someone would also have considered that by now.
Bottom line is that really the only people who can advise you are the ones who know the details of your epidural insertion (and details of your delivery), the results of your MRI & any other tests you’ve had and the findings on examination. Hope that helps.