だらけ、ばかり

"だらけ" indicates a state where something exists in large quantities. It is placed after a noun to mean "full of ~" or "covered with ~."

この部屋はほこりだらけだ。
このへやはほこりだらけだ。
This room is covered in dust.

カメラを落としてしまい、傷だらけになってしまった。
かめらをおとしてしまい、きずだらけになってしまった。
I dropped my camera, and now it's covered in scratches.

"ばかり" is used to mean "almost only ~" or "nothing but ~."
"ばかり" is typically used with verbs that represent actions.

私の仕事はデスクワークで座ってばかりなので、腰が疲れます。
わたしのしごとはですくわーくですわってばかりなので、こしがつかれます。
My job involves sitting at a desk all the time, so my back gets tired.

遊んでばかりいないで、勉強もしなさい。
あそんでばかりいないで、べんきょうもしなさい。
Don't just play around; do some studying as well.

"ばかり" can also be placed after a noun like "だらけ," but the basic meaning of it being used with a verb that indicates an action does not change.

彼は休みの日は、テレビばかり見ている。
かれはやすみのひは、てれびばかりみている。
On his days off, he does nothing but watch TV.

彼は休みの日は、テレビを見てばかりいる。
He spends his days off just watching TV.

In both cases, "ばかり" is used with the verb "見る" .

甘い物ばかり食べていると、太りますよ。
あまいものばかりたべていると、ふとりますよ。
If you eat only sweets, you'll gain weight.

甘いものを食べてばかりいると、太りますよ。

You'll gain weight if you keep eating nothing but sweets.

Here too, "ばかり" is used with the verb "食べる" (to eat).

In everyday conversation, there might be times when the verb that is supposed to accompany "ばかり" is omitted, which can cause confusion with "だらけ."

彼は文句ばかりで、解決策を示さない。
かれはもんくばかりで、かいけつさくをしめさない。
He just complains and doesn't offer any solutions.

Originally it should be:
彼は文句ばかり「言って（いって）」、解決策を示さない。

最近、失敗ばかりで、落ち込んでいます。
さいきん、しっぱいばかりで、おちこんでいます。
Lately, I've been nothing but a series of failures, and it's getting me down.

Originally it should be:
最近、失敗ばかり「していて」、落ち込んでいます。

There are also similar expressions like "まみれ" and "ずくめ" that convey similar meanings, and I plan to post about them in the future.