。
Reckless from childhood, I've been losing out my whole life because of it.
Literal
Reckless [is-で] child [genitive-の] time [from-から] loss [only-ばかり] do-am.
This is the second half of the famous opening line of Natsume Sōseki's 1906 novel 坊っちゃん (Botchan): 親譲りの無鉄砲で子供の時から損ばかりしている. 無鉄砲 (むてっぽう, lit. 'without a gun') means 'reckless,' 'rash,' 'devil-may-care.' The で is the て-form of the copula linking it to the next clause — 'being reckless, [I've been] losing out from childhood.' ~ばかりしている ('do nothing but X,' 'always X-ing') is a fixed habitual pattern: 損ばかりしている = 'always taking losses,' 'never coming out ahead.' The verb is in present-progressive ~ている form despite referring to a span starting in childhood — Japanese marks this as an ongoing state up to the present, where English would use the present perfect.