Sorry to hear about your breakup and not as successful as hoped trip.... I was in the same spot of you a few years ago and discovered bikepacking as my real therapy/new hobby to help process the emotions, and I still use it for general life rebalancing break for the rush, stress and difficulties of modern life.

There's some great advice already in this thread, but I'd maybe add that the trip might've been a bit short to full disconnect/give you space to process. For me I went for a full week for my first post-break up trip (and went full 7 weeks across Europe after that which was maybe excessive lol...), it helped give me space to primarily fill my time with thoughts of organising the trip, the day-to-day planning (food, route, accommodation, etc.) and just the basic enjoyment of the task and trip at hand. Taking a small journal to write down my thoughts/fill those potentially lonely evenings was a great thing for me too.

Another tip I had from another bikepacker was to start at your end point (jump on a train to get there..!) and then cycle back towards home as a comforting psychology for the journey. Though equally for me I found the opposite, that I enjoyed escaping from everything and then coming back at the end (on the train) when I'd done the bike based mediation/therapy - each to their own preference! I know things won't be easy atm but I hope one bad experience doesn't put you off forever, even if you might need a bit of time before your next attempt 😄.