... I'm now learning that ARMORY requires Bitcoin Core to function but I don't even have 300GB of space to be able to download it. How can I go about recovering them?
Don't stress... it's very easy to recover your funds. You can refer to my guide here:
https://bitcointalk.org/index.php?topic=4746784.msg43255691#msg43255691You will be able to export the private key for your 136d5ebKCiXH7KSA9Ykd5wqVRKdkXQpNrY address... then import that key into another wallet. For ease of use, I would recommend using Electrum:
https://electrum.org/#downloadSimply use "Import Bitcoin addresses or private keys" option when setting up the wallet in Electrum and copy/paste the private key that matches the 136d5ebKCiXH7KSA9Ykd5wqVRKdkXQpNrY address. It should start with a "5"... Refer:
https://bitcointalk.org/index.php?topic=4746784.msg43432393#msg43432393NOTE: I would not recommend using the single address, "imported" wallet in Electrum long-term, you should either create a new "standard" wallet in Electrum with a seed mnemonic backup and send your funds there, or send your funds to another wallet of your choice.