daidokoro de ajimi bakari shite itara, bangohan no mae ni mou tabetaku naku natte shimatta.

で marks the place where an action happens.

• 台所で = in the kitchen
• The action is 味見していた (was tasting / sampling), so で is the correct particle.

Compare:

• 台所で料理する = cook in the kitchen
• 台所にいる = be in the kitchen

Use で for where an action takes place, and に for where something/someone exists or goes.

味見 means tasting food to check the flavor.

It is not exactly the same as eating a meal. It usually implies small bites taken while cooking.

So 味見ばかりしていたら suggests the speaker kept sampling the food during preparation, probably little by little, to the point that it affected their appetite.

Here, ばかり means nothing but, just, or too much of one thing.

So:

• 味見ばかりしていたら = if/when I kept doing nothing but taste-testing...

This often carries a nuance that the action was excessive or repetitive.

Examples:

• 遊んでばかりいる = do nothing but play around
• 甘いものばかり食べている = eat nothing but sweet things

In this sentence, it suggests the speaker sampled the food so much that it caused a problem later.

していたら comes from している + たら.

• している = be doing
• していた = was doing
• していたら = while I was doing / when I had been doing / if I kept doing

This emphasizes an ongoing or repeated action in the past.

So:

• 味見ばかりしたら would sound more like if you taste-tested a lot or if you did that
• 味見ばかりしていたら gives the feeling of while I kept on taste-testing

That fits the situation better, because the speaker gradually lost their appetite through repeated sampling.

Here 〜たら is closer to when/after doing that, the result was..., though if is sometimes used in translations.

The pattern is:

• A していたら、B になった
• while/when I was doing A, B happened

In this sentence, it describes a natural result:

• 味見ばかりしていたら、食べたくなくなってしまった
• After/while doing nothing but taste-testing, I ended up not wanting to eat anymore

So it is less about a hypothetical condition and more about what actually happened.

The の links the nouns:

• 晩ご飯 = dinner
• 前 = before
• 晩ご飯の前 = before dinner

This is a very common pattern:

• 学校の後 = after school
• 寝る前 = before sleeping
• 食事の前 = before the meal

With nouns, you usually use の前.
With dictionary-form verbs, you can also say things like 食べる前 = before eating.

Here もう means already.

• もう食べたくなくなってしまった = I had already gotten to the point where I didn’t want to eat anymore

It emphasizes that the loss of appetite happened before dinner even started.

Depending on context, もう can also mean any more, but here already is the natural meaning.

This is built step by step:

1. 食べる = to eat
2. 食べたい = want to eat
3. 食べたくない = do not want to eat
4. 食べたくなくなる = to become not wanting to eat
5. 食べたくなくなった = became not wanting to eat / no longer felt like eating

So the sentence is not just saying I didn’t want to eat. It says I came to not want to eat anymore.

That change-of-state idea is important.

Because 〜たい behaves like an i-adjective.

Just like:

• 高い → 高くない
• 寒い → 寒くなる

you get:

• 食べたい → 食べたくない
• 食べたくなくなる

So:

• 食べたい = want to eat
• 食べたくない = do not want to eat
• 食べたくなくなった = became not wanting to eat

This is a very common pattern with 〜たい.

〜てしまった often adds one of these nuances:

• something was completed fully
• something happened unfortunately
• something happened unintentionally
• a result was more extreme than expected

Here, 食べたくなくなってしまった suggests something like:

• I ended up not wanting to eat anymore
• I went and made myself lose my appetite

It adds a slight feeling of regret or oops, that happened.

Without it:

• 食べたくなくなった = became not wanting to eat

With it:

• 食べたくなくなってしまった = unfortunately ended up no longer wanting to eat

Because 味見する and 食べる are not exactly the same action in Japanese.

• 味見する = sample the food a little to check the taste
• 食べる = eat properly, as a meal

So the speaker is saying:

• they kept sampling
• as a result, by the time dinner came, they no longer wanted to eat the meal itself

Using both verbs makes the contrast clear.

Yes. Japanese often leaves out the subject when it is obvious from context.

A natural English interpretation would supply I:

• I was doing nothing but taste-testing in the kitchen, and before dinner I ended up not wanting to eat anymore.

But the Japanese sentence itself does not explicitly say 私.

This is normal and very common in Japanese.

It can be broken into two main parts:

1. 台所で味見ばかりしていたら

   • while/after doing nothing but taste-testing in the kitchen

2. 晩ご飯の前にもう食べたくなくなってしまった

   • before dinner, I had already ended up not wanting to eat anymore

So the flow is:

• location: 台所で
• repeated action: 味見ばかりしていたら
• time reference: 晩ご飯の前に
• resulting state: もう食べたくなくなってしまった

This is a very typical Japanese sentence pattern:
ongoing action or condition → result.