So what was wrong with Rob in Season 10

In season 9 Lamar was on the run with crack and Rob was just fat with possible thyroid problems. Now in season 10 he’s “gained 100lbs and missed Kim’s wedding.“ He also was spending a ton of money. Honestly his behavior mirrors what we see in season 12/13 when Lamar relapsed and was asking for money. What is really going on here? Also why was he starting the first round of meds and leaving for 21-30 days. Was this some type of intervention that they were trying to cover up?