Stock value goes down then goes back up and have to pay taxes on the increase. Next year same thing. Is there no credit when the stock decreases in value?

The increase or decrease in value of a stock that you hold without selling is not reported on a tax return.

Where are you seeing taxes on the increase?  Did you sell something or just reporting the dividends?

You only pay tax when you sell it.  You pay tax on any gains you actually got from the sale.  You enter the sales price and your cost and Turbo Tax calculates the gain or loss.  If you sell at a loss you can deduct up to 3,000 on your tax return after applying the loss to any gains.

You should get a 1099B for sales.  You have to upgrade to Premier to enter investment sales.

did you take a loss on your return in the year the value went down?   you do not take a loss until sold and there's a rule if you repurchase the same security within 30 days of the sale, the loss isn't allowed.    if you took a loss for the decrease in market value you need to amend that return.