If you have been TTC for 2 years already it is time for you and your partner to go to a fertility clinic to get checked on chances of fertilization from the both of you.
Smoking greatly affects fertility and sperm count among other daily living activities.
There are many options out there that can help your chances of conceiving.
If you don't mind me asking, what is your age? I see by your name "Oma" which means grandma in german - are you of that age (menopause)? If so, even peri-menopause causes ovulation to slow down thus you are not releasing eggs every month and your chance of conception without a fertility clinic is almost nil. Remember with age we release and lose eggs more than when we are young.
Remember lots of babies out there without parents need adoption and how about a surrogate mother? Just giving you more options to think about.
Hope this helps and good luck!