There are other ways, though the trade-offs are potentially less desirable.
A couple of things that it might be helpful to clarify:
You mentioned having potentially deleted some tags. If that’s the case, the cards to which they were attached are likely still present (just no longer tagged). Deleting tags won’t, by itself, delete cards.
The way that I mentioned above, resetting local changes, will restore the tags you deleted.
Separately, you can also consider restoring from a backup. This is likely to be a slightly more drastic option, which I’ll explain: Anki makes backups for you, periodically. You can also make them manually, though they’re made automatically regardless. Each backup is a snapshot in time of your collection at that particular point in time.
Once you have a backup you can restore from it. The issue here is that you are, necessarily, going back in time. So we’ll use your case as an example:
Do you know when you might have deleted the tags? If it was yesterday, restoring from a backup can be a viable solution. But let’s say it was a week ago. Restoring from a week-old backup can be done, no question, but inherent in that is also losing any review progress you’ve made in the last week (which it sounds like you’re hoping to avoid).
Certainly either option can work, though given my understanding of what you’ve described, and what you’re trying to do, the resetting local changes option that I described above likely remains your best option.
Please let me know if that answers your question and if there’s anything else I can help with. 