Single Dad Struggles to Build Bond with Son: Seeking Advice

Hi Anu ji, I am 42 yr old single parent. I have a 10 yr old son living with me. My wife and I were separated when our son was 3 yr old and we recently settled our divorce. Immediately after our divorce, my ex-wife got re-married. Her husband isn’t willing to take my son in and hence she handed over his legal custody to me. She has moved on with her life and my son doesn’t feature in her list of priorities. I am more than happy to have him. During the last 7 years of separation, she did not allow me or my parents to meet my son, so we could not build a strong bond together. Now, it has been 6 months since my son has moved in with me. Its only me and him living together ATM. My parents stay in our ancestral village and are unable to stay with me. Though its challenging for both of us to discover and understand each other, it must be tougher for my son. He understands the fact that his parents aren’t together and hence he has to stay with either of us at a time. Sometimes, he does get emotional about this situation not being normal compared to his friends / cartoons / movies etc. He also misses his mother and often keeps quoting that “My mother does it this way...”, “Me and my mum used to do this / that” etc etc and I appreciate that. I am fine with him talking to his mother through WhatsApp and meeting her whenever they wish to. He is also close to his other maternal family members, and I do not have any issues with him maintaining that bond. Now the challenge is, my ex-wife and her family abuses and shoos me away every time I try to ask them about my son such as his eating habits, likes, dislikes, vacation plans etc etc. They also bad mouth me whenever they speak to my son. That poor little soul gets influenced and feels that its punishment for him to live with me. And I feel betrayed as I too have made sacrifices / adjustments in my career, relationships etc to be able to take care of my son. I feel like stopping his communication with his mum and maternal family, but worried if that would adversely affect him. Now I have also started to get angry whenever he speaks to his mum or maternal family and try not to vent out at him, but I sometimes I do. Please guide me to navigate this delicate situation and what should I look forward to in my life.