How to get re-hired

Status: 1.7 yoe | Passout from Tier 3 Position: SDE1 at a product based company (Java Backend) CTC: 5.2 lpa I resigned from there in April because of personal health reasons plus the work environment and the pay did not suit me well. I was confident to find a better pay as compared to how/the amount of work I got done there in comparison to my peers but unfortunately I feel lost now. From last two months I am focussing on my DSA concepts, and now feel a bit confident to start interviewing again.

One of my concern is will this type of career break impact seriously or is that acceptable to companies. Secondly, sometimes I also get confused on should I focus on the core subjects again thoroghly or just grind leetcode properly first and then maybe a week or so on OS, DBMS, OOPS, Java, Spring Boot (based on my last project at work). Kindly give some assistance on time partitioning since I am getting overwhelmed in order to get myself "fully prepared". Also pls help me with referrals, if any.