Most likely scenario here is that your wallet is not synced fully yet or you entered the wrong address when performing the withdrawals. Checking none of the outputs from the txid you shared match the amount you say you received in your wallet. Did you have a balance before which is likely what you still have available in your wallet?
You do not need to perform regular backups, because your wallet can be recovered from a secret phrase that you can memorize or write on paper.
You should never memorize your secret phrase and you should test it intermittently, just to make sure.