Apart from the fitness benefit, a hiking group offers the chance of casual social connection, and connection may be very helpful to you at this stage. You ruminate a lot, (as people do in recovery) and social connection in a congenial group with shared interests - like hiking - could give your mind a break from rumination. Rumination can become a habit, and actually works against us after a while by reinforcing the old abusive neural pathways of victimhood. You don't want that and you deserve much better. You see that clearly now! One way to break that pattern is to replace it with a better habit more consistent with your overall goals. I think safe healthy connection is really important during the first two years of recovery. As we change our behaviour and act differently, we change our thought patterns, and that builds new neurological pathways, so that instead of being stuck, we are actually creating new ways of being on a cellular level. What power we have... Your choice now is an important one, and you are wise to reflect on it carefully.