I work in germany so I do have an income but not a W2 form. How do I fill out the part about my income tax ?

You can enter foreign income without any forms, actually. It has special data entry and it accounts for all situations of foreign income.

To enter worldwide/foreign income in Turbo Tax:
    1. Federal Taxes
    2. Select Wages and Income
    3. Scroll down to Less Common Income

Select Foreign Income and Exclusion - Answer “Yes” to “Did you make any money outside the United States?” and follow the interview questions. You will be asked to enter income from a U.S company, a foreign company, self-employment income, housing allowance, income from a Form W-2, 1099-MISC, schedule K-1 from a business or simply cash income - check the box A statement from my foreign employer (could be cash).