Well, never mind. That's just my level of English.
It can't be helped. My English is still at this level.
Never mind. I did my best.
「しょうがない、私の英語力はこんなもんだ」＝ Well, never mind. That's just my level of English. / It can't be helped. My English is still at this level. / Never mind. I did my best.
ボキャブラリー
しょうがない、し方がない ＝ never mind / it can't be helped
level of English ＝ 英語のレベル
do one's best ＝ 頑張る
イギリス 
