Tips how to super bulk?

Last year i was able to gain 18kg going from super skinny to kinda bulky. 2 months ago i got prescribed meds for ADHD and it completely shattered my appetite, lost 7kg and im afraid imma be just skin and bones again in a few months. Any tips on how to mine as much as i can from the little appetite i have now and atleast not lose weight this drastically while in getting used to my meds? Like some forbidden technique yall ever discovered. I can absorb food much better in liquid form than solid