Good advice in this thread. Fire the financial adviser. If you like, you can simply pay to talk to a tax accountant for half an hour or hour, if taxes on the windfall are a concern. If you got the windfall in 2018, you have until April 15 2019 to make an IRA contribution for 2018, so don't have to decide anything this minute.
Based on what you've said (and without knowing more) it sounds like a traditional IRA might be a better than a Roth for your situation and here's why: With a traditional IRA, you get a tax break now, and then pay taxes when you withdraw the money. With a Roth, you pay taxes on the money now, and the withdrawals are tax free in the future. If all things are equal, it works out to be exactly the same, tax-wise. That's assuming tax rates stay the same, which nobody knows of course.
But all things aren't equal (or probably not, anyway). If you go with the traditional IRA, you'll get to keep more of your windfall, which you can then invest in a regular taxable account, so you'll wind up with more money in retirement. Plus, you get the tax deduction at your highest marginal tax rate. Presumably, when you retire your income goes down, and hence your tax rate goes down. So, in theory, you'll pay less tax overall.
You'll want to look into this some more of course. But that should at least give you an idea what to think about and what questions to ask.