You're young and this too shall pass. It's normal to feel anxious about things we are also excited for. It's a way your brain is planning for your life and tryi

You're young and this too shall pass. It's normal to feel anxious about things we are also excited for. It's a way your brain is planning for your life and trying to optimize it and, as a programmer, you probably have a brain that's pretty good at that. If the thoughts are getting in the way of your life, for example causing you to stay curled up on the floor for more than five minutes, it's okay to redirect them. You're not going to "miss out" on your life's best decision by only allowing yourself five minutes to obsess on the future per 6-hour timebox. So, when they occur, accept the thoughts for a while, if something emerges that you think is a good plan write it down, and then after the five minutes are up get up and call a friend, do a physical activity, or put on a song you like. If the same thoughts recur too often you can allow yourself to ditch them; tell yourself "I always think [that I can't afford a house] and it never leads to a good place!" and then make a conscious effort to think about how much you'd like to renovate a house or people in your life who have mortgages and still go on international vacations. Above all, everyone I know who's over 25 has been there, and we're still alive. You'll be us someday.