My 3DS is very unstable

Whenever I close my 3DS lid too hard or just sometimes out of nowhere it says that the SD card is unreadable and i lose access to all my games. I then have to reboot it and reinsert the card a couple of tines until it starts working again. Could anyone help me fix it? My 3DS is the CTR-001 (JPN) modded with Luma3DS.