Trying to block your twin would be trying to block you from yourself, both are equally painful in the process to attempt, as they are both equally impossible to do. All hard lessons that I had to learn myself on my journey. I used to describe my journey as a rollercoaster of extreme highs and just as low of lows (your description of the boomerang effect I feel is perfect). What you discover is the need and desire for balance, our natural state of being but we forgot.
The obsessive thoughts were painful. In the process of healing and the desire not to “chase” you start to tell yourself that you should not think of them at all. Even if the slightest thought comes up, you divert your mind and busy yourself with something else in the times that you may see yourself as ‘strong’. In the weak moments, you get mad at yourself for not doing what you ‘think’ that you are supposed to do. The problem with all of this is that you are trying to process the feelings with the analytical mind, and that will never work in the end. I do much better now just feeling into it. I allow it as opportunities to open up telepathic communication to see what he has to tell me or what he wants to show me. The acceptance of the journey in understanding that we are one and not separate helps with the surrender of the moment.
There were definitely times that I tried to tell myself that what I felt wasn’t real, that it would all just go away with time. Needless to say that was not the case. I believe that this journey is one of ultimate self-love. Yes, we are one, so loving our twin is the same as loving ourselves, but it goes so much deeper then that. It is the love that we allow ourselves to receive from our twin, even energetically, that transcends the physical reality. The belief in that inner voice, our inner-guidance system, our intuition, that says “this is real, love yourself by allowing your twin to show you love”.