There are two distinct questions here.
The money transfer is easy. There are no taxes on transferring your own money from bank to bank, even if the bank is overseas. The banks will report the transfers as part of routine reporting, you don't have to do anything. However, if at any time during the year you control a foreign bank account with more than US$10,000 in it, you must report that fact online in an FBAR report.
https://www.irs.gov/businesses/small-businesses-self-employed/report-of-foreign-bank-and-financial-a...
If this is your money, being temporarily held in your father's bank account, then technically you still don't need to file any forms. There is a form 3520 that you file if you receive a gift of more than $100,000 from a foreign person. Even though this might look like a gift to an outsider, it sounds like this is your money all along, so I do not think form 3520 is needed.
The income question is also fairly easy, but you're not going to like the answer. If you are a person subject to US tax law (meaning you are a US citizen or green card holder living anywhere in the world), then you report and pay US tax on all your world-wide income. The cash surrender value of a life insurance policy is taxable income as ordinary income (not capital gains) to the extent that the payout is more than the cost basis. You will also owe state income tax if you live in a state that has income tax. The cost basis is the total of your after-tax premiums.
To determine the cost basis, you need to know the US$ value of the premiums you paid, this means going back and figuring out your premiums for each year, in DM or Euros, and converting that to USD equivalent. The Treasury Department publishes annual average conversion rates you can use instead of looking up the daily rate for every single payment.
https://www.irs.gov/individuals/international-taxpayers/foreign-currency-and-currency-exchange-rates
Then the amount of income is the difference between the premiums (in USD) and the payout (in USD on the date you received it). The income is taxable as of the date you cashed out the policy, even if you did not transfer the cash to the US right away. If the payer was a US company they would issue a 1099-R. Since the payer is not a US company, you will have to prepare a substitute 1099-R in Turbotax. Enter the total payout as box 1 and the taxable amount (determined from your own records) as box 2a.
If you also paid tax on this income in Germany, you can claim a deduction or credit on your US tax return.
