Database size is increasing and having performance issues

Hello Everyone,

We have two management servers and around 60+ agents in our environment. It is SCOM 2012 R2 version(recently upgraded). Initially the data warehouse size got increased and then we restricted the size growth. Later tempdb is growing in size and filling up the disk space so we have restricted the growth of the tempdb as well. there are so many error messages in event viewer that data dropped and data could not be written to database as DB is full.
For 70 agents, our DB size is 123GB and DW size is 224 GB.

Can you please suggest me how to reduce the size of these databases or how to perform the maintenance tasks? Fine tuning of monitors and rules are done. We have performed already shrink operation and it is not working.