"We cannot do everything at once, but we can do something at once." --Calvin Coolidge
Do you know what the root cause of self-sabotage is? A hyperactive obsession with the road ahead. Let me explain:
Yes, it's essential that you are able to plan, project outcomes, and forsee obstacles in order to reach your goals. But at times, this ability to see into the future backfires on us. The very thing which enables you to pursue your goals is also the same mechanism which can leave you utterly paralyzed. The difficulty of the path ahead (as we think we see it) can murder our motivation. We become overwhelmed by our (often incorrect!) anticipation of the work. This, in turn, causes us to put off working towards our goals.
In the pursuit of goals, the happiest people are the ones who hike the trail one step at a time. They accept that they can't know the exact conditions of the terrain. They may have heard some crossings are difficult, some bridges may be out. But what do they do? They walk the path available. They follow their compass. When the time comes they have to cut a new trail, they break out the machete and trailblaze as required.
It's more important to have tools at your disposal to handle challenges than it is to have all of the challenges figured out in advance. Don't visualize the hardships! Trust yourself and set out armed with the best tools available at the time.
Overcome self sabotage! Embrace the work in front of you. Improvise when called for. You can't do it all at once, so do what you can right now.