Without knowing more about you total situation it is hard to offer more than some general (may or may not apply to your specific situation) comments.
Do you have other taxable income that can be postponed (ie 401k/IRA withdrawals) so you can sell part of your stake without affecting your tax situation? Keep in mind that your gains may be subject to long term capital gains taxes only.
If you are drawing Social Security then too much income can cause those benefits to be taxed... That is a consideration.
I think you probably need to discusss the tax consequences with a tax advisor (or accountant). My guess is you want to set up a program to sell part of your holdings now and then sell a portion at regular intervals to avoid a huge tax hit in any one year. But, this is strictly a guess based on incomplete information.
If you decide to not sell then I would suggest you consider selling covered calls on all or part of you holdings to generate additional income to supplement the dividends. You need to monitor this to make sure you only get called on an amount that you are willing to sell in any given tax year. Good luck - your problem is a good one to have.