Well, Trinity’s snapshot transition feature doesn’t generate and display addresses like the older wallets did, it just checks them. If it doesn’t find any balance, you’re not using the same seed you used to receive funds.
If you want to look at more addresses of you seed, you can still generate as many as you like with the Lightwallet. It doesn’t get updates anymore and is therefore not recommended to use, but it still works.
You said you used some old Android wallet. I know nothing about these because none of them was official. But did your old wallet app maybe store your seed somehow on your phone? You could ask the app’s developer if there’s any chance to recover your seed from the app data or something.
The only thing I know about Google play notes is that it’s definitely not a recommended method of storing seeds. But, deleted data of all sorts can be retrieved sometimes and I think it’s worth a try to ask around in the #help channel on Discord. It’s full of very smart people, maybe someone has an idea. Here’s an invite link: https://discord.gg/hgbDnBd
If nothing helps, your funds will indeed be lost. IOTA is a decentralised, distributed ledger, which means that it’s not owned by anybody. Being your own bank, without having to trust some middle man, is actually the purpose of this and that makes it very different from losing access to your bank account. You are the only person who has the key and if you lose it, there’s nobody else who could access your funds and return them to you.
When you buy IOTA (or any other crypto) again, make sure you have more than one backup of your seed. Don’t store it on your device or if you absolutely have to, at least use KeePass and also copy it on a piece of paper. Test if your backup works by checking if you get into the same account with the same addresses before you really start using your seed.
Best of luck, I hope that you'll find your seed!
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