I want to attach a heat sink to the inductors on my motherboard, which glue could I use?
It might not solve your problem, but to answer your question:


  I want to attach a heat sink to the inductors on my motherboard, which glue could I use?


Since there is no feature to mechanically mount a heatsink, adhesives must be applied.
Thermally conductive epoxy does exist, but it is rather expensive. (eg: 3M TC-2810)
More suitable would be thermally conductive dual side tape. (eg 3M 8810)



Back to your problem: You have one of the cheapest motherboards (€50*), and fitted the highest power Ryzen 7 processor (105 Watt). This is not the intended configuration of this motherboard, power throttling is to be expected.
I recommend going with the 65 Watt Ryzen chips for this motherboard.

*Only two boards are cheaper!