Congratulations on your 100 days sober!
Like you, I recognized that a relapse for me, began with getting caught up in the negative thoughts. Sometimes, I just longed to let go and to wallow in negative stuff and I realized I don't have that luxury. For me, it's a slippery slope on the way to hell.
And, the first few months of sobriety are to be treasured because they show you that you have unlimited opportunities.