。
My love grows stronger the more it is rejected.
Literal
Be-rejected [to the extent-ほどに] grow my thought.
A poetic/literary line about unrequited love. 撥ね付ける (はねつける) 'to flick away, reject' is a compound verb — 撥ねる ('to flick') + 付ける ('to attach, add to'). The ~ほどに ('to the extent that X') is the literary form of ~ほど. わが ('my, our') is the classical/literary possessive, preserved in poems and formal writing. 思い in this context means 'feeling, love, emotions' — heart/affection, not just 'thought'.