The error message did not say that you had too much money in your HSA; I am sure it said that you had contributed more than the annual HSA contribution limit for the year to your HSA.
The normal annual HSA contribution limit for a Single coverage in an HDHP in 2018 was $3,450 ($6,900 for Family coverage). HSA owners 55 and older get a $1,000 increase.
However, your contribution limit can be reduced by a variety of factors, such as how many (and which) months you had HDHP coverage, whether or not you were covered by other insurance at the same time (such as going on Medicare), whether or not you changed coverage (Single to Family and vice versa) during the year, and so on.
The screen that told you that you had made excess contributions and would you like to withdraw them should have told you the amount of the excess. Since we cannot see your tax return, in order to answer your question, please tell us how much you contributed to your HSA (usually the code W amount in box 12 on your W-2), the amount of the excess that TurboTax reported, and whether you had Single or Family coverage from your HDHP policy. Also tell us which months you had that coverage.
It can happen that the user can accidentally indicate to TurboTax a situation that makes TurboTax think that you made an excess contribution when perhaps you didn't.
Give us the details and we'll work out what you need to do...
No. HSA money is yours to keep. Unlike a flexible spending account (FSA), unused money in your HSA isn't forfeited at the end of the year; it continues to grow, tax-deferred. Once funds are deposited into the HSA, the account can be used to pay for qualified medical expenses tax-free, even if you no longer have HDHP coverage. The funds in your account roll over automatically each year and remain indefinitely until used. There is no time limit on using the funds.