Can I use the capital gains taxes I paid for my mutual fund in previous years when i sell shares now in my mutual fund?

No and kind-of-Yes....depends on what you mean.

1) IF you received capital gains distributions in prior years, and just had those $$ entered into a cash account, then no, you cannot.  Those Gains were taxed  (i.e. they were reported on a 1099-DIV form, from the fund company)...but you kept the remainder in cash.

2) IF you received capital gains distributions in prior years, and just had those $$ rolled back into the fund, then those $$ were also reported and taxed on a 1099-DIV at that time, and the amounts that were used to purchase new shares.  BUT, the $$ going back in just add to your basis, making the Gain when you sell smaller.  So it's automatically taken care of since the fund company (usually) takes care of that basis.

3)   similar to #2, but a However. if you bought shares in the Mutual fund before 1 Jan 2012, and had 1099-DIV  Capital Gain distributions re-invested before that date, then the Fund company might not have you true Basis for the shares bought before that date.....you might need to supply that basis yourself from whatever records you keep.  Some companies have it, and report it properly on a 1099-B/8949 even if acquired before 1 Jan 2012, as long as they held all of those shares themselves.....others may not fill in the basis boxes on the 1099-B/8949 forms even if they have it, but may have that basis ready for you to fill in yourself on the tax forms.  BUT...if you transferred mutual funds from one brokerage to another before 1 Jan 2012, then the new brokerage won't have that basis $$ amount, and you'll have to supply it form your own records  (yearly summaries you needed to have saved form all those years ago).