I'm working hard to make up for the time I wasted.
Literal
Wasted time [object-を] make-up-for [so-that-ように] giving-effort work-[progressive-ています].
埋め合わせる ('to make up for, to compensate for') is a compound verb (埋める + 合わせる). がんばる ('to work hard, persist') in te-form + 働く = 'persisting, work' = 'work with perseverance.' ~ように marks the purpose. Self-improvement statement.