This is not a visa but an entrance stamp. As you left Thailand already, it is not valid anymore. On your visa is the last day that you can enter Thailand. If that has already passed you need to apply for a new visa
What do you mean by “the right way”? Try to have your money, that was transferred in from your bank account abroad, sent back to that account, if your are not in Thailand and only have a normal savings accounts (a fixed deposit account is even better). Enjoy the experience
Money transfers into Thailand are easy (getting it out again is another topic). But have you thought about visa and health insurance issues? That’s when it really gets tough