You needed a new channel to send more sats, when you sent the first set of sats, you created a channel and then all the sats pushed to your side, meaning you had no room for more. When you sent more, you needed another channel to receive them.

If you sent them all from the same place, your mistake was not sending them all at once.

If you’re using pheonix to RECEIVE sats, you will need to spend all your sats to make the liquidity change from outbound to inbound.

If you’re trying to spend from pheonix, you can do that now as your liquidity is all outbound at the moment.