Why did it come back?

I’m wondering if this has happened to anyone else… I’m 28 years old. I was diagnosed with OCD when I was very young and it took a while, but I overcame it. I haven’t had any compulsions in 20 years. I’ve had some horrible things happen in the past, but nothing brought back my OCD. The only thing I struggle with is overthinking and making decisions. Im about to take a sabbatical from my work for a year to travel because the last year of my life has been by far the happiest and most confident iv ever been. I went to see a therapist a couple weeks ago who was an OCD specialist, I just wanted some tips and tricks for decision-making while I’m on my trip. She warned me that my OCD might get worse before it gets better, but I thought that she just meant with decision-making and overthinking. They have this program set out that I didn’t really wanna do but she told me it works really well so I decided to try it. It’s two sessions a week and the first two sessions were sort of just talking about my old OCD and doing questionnaires. I really related to some of the questionnaire questions, and the therapist was actively telling me that I definitely had OCD the whole time which made me feel bad. After our second session, my OCD came back full swing like when I was a child. I cant stop thinking about doing compulsions every waking second. It’s been two weeks. I’ve been to her several times and nothing is helping, I’m resisting the urge to do compulsions as much as I can and I feel like I’m fighting for my life. Nothing is helping and I’m burning out. I wake up and cry everyday because of how uncomfortable and out of control I feel. I never thought this would happen and im so mad at myself for ruining my trip. I feel like I’ve ruined my life tbh and even if I do get better, I’m always gonna be bothered by the constant fear that even at the highest and most happy points in my life it could just come back at any second with no warning signs.. I thought I knew how to deal with it and had the tools, but nothing is working this time and its ruining my life. Today I asked about cancelling my trip altogether, and I might be going on medical leave. Has this happened to anybody and do you have any tips for me?

Does anyone like go through waves. Your mind is super silent maybe a couple of thoughts but you are able to brush it off? But then out of nowhere your mind just starts rushing with every thought? If so, how do you cope with this? It drains me.

These past few days I was fine. Minimal intrusive thoughts ,no anxiety etc(to add I'm on medication so maybe it's starting to work although it barely is 2 weeks) and today I got a sudden wave of anxiety and it started latching on some thoughts like" what if I'm in denial and I wanna break up with my bf? And what if erp doesn't work for me because I actually wanna break up with my bf?" But they didn't really stay long usually those thoughts would make me spiral for days or so, now they lasted for some hours. And now I'm trying to trigger myself into being anxious again because if I don't it means I don't have ocd and if I don't have ocd it means I don't love my bf and if I don't love my bf it means I have to break up. Idk if it makes sense but the lack of anxiety makes me wonder if I actually have ocd or not.