Tried to drain it out with warm water, but it didn't work. is this lump actually a sebaceous cyst or is it something else?

It's real hard to : Tell if i cannot see it or feel it. If you have been "working on it", it may now be an infected whatever it was in the first place. Go to an urgent care center, let them decide if it can be drained, or needs a surgeon to work on it.

Epidermal cyst?: This could be an epidermal cyst, which is an encapsulated collection of dead skin. Draining it often doesn't get rid of it. Usually, it needs to be surgically removed.