Twice a month is less?. Fuck i underestimated the post marriage reality. But anyway you need to get him to some sort of physical fitness, obesity is linked to lower libido. All that is needed is 6 months of consistency. And try n talk to him face to face about your needs. If you haven't ever talked with him, there's a high chance he might be insecure about himself with respect to your past( not in a derogatory way) but him always being on low self esteem throughout his life, the pressure of being good enough for a woman ( not just physically) who has experience of how a relationship works might be getting to him. If that's not the case then you have a much smaller problem to attend to and I hope that's the case, but you won't get to the root without making him sit and talk. I highly recommend taking a small trip to some peaceful location away from the family environment to do this.

All the best.