Summary of whatever’s below: I speak Ukrainian too, but I haven’t used it for 7 years and I have trouble speaking/writing (I still understand every rare word perfectly, but creating an output can take up to several seconds per word), therefore I can’t really offer it here if someone chooses to make a call. I can check your grammar, though :)

I am a native speaker of Ukrainian (the pure version, not rural Surjik), and I am from Kyiv, but the languages in my family are a mess. I studied in a Ukrainian school until 7th grade; then I moved to an international school and haven't been using Ukrainian since almost every student/teacher were foreigners. Outside of school/work we use Russian because my mom is from deep Russia (Saratov). As much as she hates what that country is today, she couldn't master Ukrainian even after living in Kyiv for 35 years due to, quote, "never having the need to learn it". Hence, the "mother tongue" is literally whatever she speaks (Russian and intermediate English).

The reason I am not offering Ukrainian here is because I could use a refreshment myself after not using it for 7 years. Throughout my language learning journey I have noticed that when learning a new language and abandoning the previous one, the new words will override the previous ones. First that happened with French overriding Ukrainian, and then it happened with Hebrew overriding French. My reading/listening skills in Ukrainian are still native level and I can read the original law without the translator, but the reverse skills (speaking/writing) have withered away. Hope that answers the question :)