US citizen here, and a resident of Kharkiv.
All I can say is I am glad you found a more effective way to give to the cause than I did.
I tried to fight (hey, as a combat vet, I thought I could be useful). They said with an injured leg (details in my blog), and no knowledge of the Ukrainian language (so I can neither understand nor relay orders) I am of no use. So I gave a few basic police tactics lessons to the civilians at my local shelter (the government taught them how to make molotovs, I taught them that a can of aerosol deodorant duct taped to the end of the bottle with a few nails made them fragmentation grenades) and bugged out.
...To be honest, I will live every day of my life with the shame of having left. I should have stayed to fight. A cop is not a soldier but I should have stayed to give at least those skills.
I am glad you have found a way to help Ukraine more than I did. I write articles but they are worthless.
This is what all good people say and feel. the thing is... everyone cannot fight. And everyone cannot be where there is military action. Each of us has a role to play in this war. We just don't give up and find an area where we can be useful. There is no shame in that you left. You can be useful (and I believe you are!) there where you are. Just don't give up ❤️