While "love" in Swahili is "upendo", there's no direct way to combine them into a phrase like "Thank love" in English.
However, you can express gratitude for someone's love by saying:
* "Asante kwa upendo wako" (Thank you for your love)
* "Ninawashukuru kwa upendo wako" (I am grateful for your love)
These phrases express the same sentiment as "Thank love" in a more idiomatic and culturally appropriate way in Swahili.