How can a roth IRA lost $170 in 3 days? ?

Don't look at what it is doing. Invest and leave it alone. 

That's what stocks do.  They go up and down.  Over a long period of time, like 30 years, you usually gain, but on a day-to-day basis, it's pretty random.

You invested in stocks, and in bonds.   These can be volatile.  The value of your investment may go down as well as up.    There have been far more dramatic stock market falls than the one you describe!

Sounds like you aren’t picking the stocks yourself. Generally you sign up for stocks with different risk levels. Think about this wonderful opportunity in front of you. 4 months ago, stocks in general were selling for 20 to 80 percent more than they cost today. The reason the value has fallen is due to the virus. The virus will go away, and stocks will return to their prior values. Today the Dow fell 700 points because of increased virus infections. I’d stay with the stocks. I bought 3 different stocks today because the prices were low. When the market goes substantially high, is when you sell. Most people do this wrong. They see a stock going through the roof, and they buy. When their stocks go too low they sell. Don’t do that. Buy low and sell high. 

Advice: go to 0% stocks because you do not understand what investing means.

Any stock on the stock market varies by 2-3 points from day to day.  If you bought 1000 shares of something, it might go up or down one or two points tomorrow and you will have gained or lost $2000-3000.  But over time it goes up. 

This is why they say you shouldn't check your stocks every day.  Let 'em sit for a month or two.  Over several years they will go up overall.  Every 7 years or so there's a recession and everything goes down, but they will come back up again and move from there.   If you picked good stocks.

I would bet that you are in mutual funds not stocks.

Also, you need to look at the types of funds in you are = high risk / high reward or more conservative.

Since you don't know what you are doing at all... call your investment company to get some help.  They will review your investment strategy with you and help you determine what investments meet that goal.

That's less than 3%.  You should not be basing decisions on day to day swings.   It's fine to look at the balance but don't go to Defcon2.

Today the DOW is down nearly 700 points as I look which is 3%.  Your change depends on what you selected but is within day to change changes. You selection (90/10 or 70/30 or whatever) is a long term decision.  When your account goes back up by $200, are you going to then move everything to stocks?  Chasing stocks based on daily moves is pretty much a guaranteed way to lose money.