一直都很爱你，只是中途走错了路，希望你能原谅我。

Have always love you, only half-way the wrong way, I hope you can forgive me.

今までずっとあなたの事が好きだった。ただ、途中で违う道を歩いてしまった。お愿い、许してくれ！

ご参考まで

Direct translation:
I have always loved you.
It's just that I have chosen the wrong path in the past.
I hope you'll forgive me.

A better way to put it in my opinion:
I really love you and I still do.
I'm sorry for hurting you in the past.
Please forgive me.