You said "I spent approx $30k for repairs etc." Repairs do not affect the amount of your gain from the sale. What is the "etc."?
The appraisal at the time of the sale was probably for the purchaser's mortgage. That appraisal does not affect the amount of your gain. You have to determine the fair market value on the date of your sibling's death. You may have to hire a professional appraiser to give you a retroactive appraisal. An estimate of value from a real estate agent is not an appraisal. Also, you cannot use the assessed value for real estate tax as the fair market value.
If you sold the house within a couple of months after your sibling died, you could assume that the fair market value did not change significantly, so the amount you sold it for was equal to the fair market value on the date of death.
You have to report the sale on your tax return for the year of the sale, and the gain will be included in your income. Whether you actually have to pay any tax on the gain will depend on your filing status and on the amount of your other income, because gain on the sale of inherited property is treated as long-term gain, no matter how long you actually owned the house.
