Not sure why you had this problem, since some members have over 7 MEGABYTES of attachments without having any issues.
Deleting those attachments probably removed them from older posts you made.
Again, I have placed no restrictions on the TOTAL amount of space the members here can use for attachments. There are individual limits on the size of a specific type of attachment (to keep someone from posting a 3000x6000 pixel, 5 megabyte file), but beyond that any member here can post as many suitably sized images as it takes to choke the server.....