I'm late to this conversation, but for future projects retaining walls generally lean outward due to groundwater pressure behind the wall. It is always important to consider how water behind a wall will be drained. As
@ceckery noted, the foundation is also very important. Most retaining walls (that are not designed by civil engineers) lean into the slope. Typically, the retaining wall blocks are designed so that each row of blocks is set back slightly from the one below (referred to as batter).
