Your dream appears to be a vivid reflection of your emotional state and the complexities of your recent heartbreak. Let's break it down:

1. Renovating the House: This could symbolize your desire to rebuild or renovate your emotional well-being after the heartbreak. The exterior looking fine while the interior is dilapidated suggests that you may be putting on a brave face, masking the hurt and turmoil you feel inside.
2. Flashes of the Finished Product: These visions might represent your hope for a better future or a desire for resolution. However, the fact that they feel disturbing could indicate your inner conflict about whether returning to this person is genuinely what you want or if it's just an illusion of happiness.
3. The Aggressive Dog: Dogs often symbolize loyalty and companionship, but in this case, the dog being aggressive and strong might represent your fears or anxieties related to this relationship. It could reflect the emotional pain you have experienced and the powerlessness you feel in this situation, as well as the duality of love and pain.
4. The Pain: The stabbing pain in your abdomen, especially as you felt a liking for the intense pain, could indicate a complex relationship with suffering. It might suggest that you are grappling with the idea that enduring pain might somehow lead to growth or self-discovery, or it could reflect a feeling of being drawn back to the source of your pain despite knowing it’s harmful.
5. Returning to the Source of Pain: The fact that you are considering going back to someone who has hurt you demonstrates the struggle between your feelings and your rational understanding. Your dream might be urging you to reflect on what you truly want and what is best for your emotional health.

In summary, this dream is a powerful manifestation of your inner conflicts following the heartbreak. It may be beneficial to take some time to reflect on your feelings and consider what you want moving forward. Trust your instincts and prioritize your emotional well-being as you navigate this decision.