Knights on b4 and g4 I suffer from knight-phobia. 

If I e.g. play white and black has knights on c6 and/or f6 I tend to play a3 and/or h3 as prophylaxis against knight coming to b4 and g4. I don't like them there. I start sensing a fork choke on my neck and lose concentration. 

Am I nuts or is this normal? I feel like I am losing a tempo. 

Do you have a therapy? Qd2? Keep on developing and react when time? Read an article by...?
This (Guide to P-R3) NM Dan Heisman Novice Nook is all that you EVER need to read to answer your question.