I think you are probably suffering from shock and exhaustion. I know I found grief immensely exhausting. I could think about nothing else for a long time and had to force myself to consider tackling daily tasks even as simple as making a drink or something to eat. Having to deal with banks and legal consequences of losing my mum were almost impossible and I had to make myself do them and often found myself trying to not to cry whilst walking down the street or talking to bank staff or whilst filling in forms. It was just all too much.
I do remember when my mum first passed away, my initial reaction was one of relief on her part, as at least she wasn't suffering anymore and had been suffering for a long time. That was coupled with sadness for myself, as I wasn't sure how I was going to cope with losing her and not having her around anymore and a fear of what the future might hold. For you, after losing so many people, that must be multiplied many times with each loss you have suffered, which in turn, will increase the fear and is probably causing the panic and anxiety attacks.
I didn't experience any numbness, but I am not surprised that you have. After all you have been through, I wouldn't be surprised if it is your body and mind's way of protecting you from any further stress, especially as your recent losses have made you so ill. I don't know that crying would help you. I had been crying for weeks even before mum died, as I felt so helpless to be able to make anything better for her and knew she was going through such a horrible time and was suffering so and I couldn't bear it. Also I knew I was probably going to lose her and that my whole life would change, so the stress of all that came out in tears and I had to struggle to keep going. I don't recall it made me feel any better though. I think it was more a release of pent up emotion, but it was not a cathartic experience for me.
It did cause me an eye problem and made me terribly tired, so in the end, I had to make an effort not to cry in order not to worsen the eye problem. I had no idea too much crying could damage your eyes. I am not even sure crying made me feel any better. I don't think it did really. I only did it because I couldn't help it. I don't recall it making me feel any better after though. I think I just cried till I couldn't anymore, but still felt as terrible as I had beforehand. Only time and my own efforts to try to feel better were of any help in the end.
I am also not surprised that your experiences have left you suffering panic and anxiety attacks and having trouble with social interaction. Loss crumbles away the foundations of your life from under your feet and makes you fearful for your future and makes it difficult to go on with daily life. I couldn't concentrate at work. I didn't care about it anymore. I couldn't be bothered to deal with people's petty concerns there. They seemed so insignificant in comparison to what was going on in my own life and with my mum. That has stayed with me to quite a large extent. I don't care about work as I used to before and I have less patience with those who stress about what to me appear to be silly things that don't really matter now. I just can't sympathize with them anymore.
In your case, perhaps you are having trouble processing how all these losses have affected you or could continue to do and that may be why you are having the panic and anxiety attacks. I think there are breathing exercises you could do and wonder if taking up yoga might also help. They encourage ways of learning to be calm and to bring peace and rest to your mind, so perhaps it would be worth giving them a try.
In terms of social interaction, I would suggest you take the pressure off yourself to engage in any situation that is not necessary for you to engage in. Why put yourself through the additional unnecessary stress? If you are faced with a potential situation you don't need to engage in if you don't want to, then perhaps don't for now and instead give yourself time to learn how to cope better with daily tasks first and allow yourself time to build up your strength and resilience again. Perhaps you could set yourself little goals for each day or week to try to deal with just one thing that you find hard to deal with and start off with something very small building up to more challenging things. I would also write down all your achievements and how you feel about them and what you feared about them. That way, you will learn what makes you fearful and perhaps be able to devise strategies for dealing with them.
It is clear that recovery and the ability to move forward is going to take time for you, but I have found the best person to help you is yourself. You just have to keep trying new things to help yourself. Some find making memory boxes they fill with items that remind them of the times they spent with the person they lost help. I put some favorite photos of my mum together in an album and that helped me a little.
I actually wouldn't worry too much about the not having cried yet. I think in your current state of mind, perhaps that is just what is right for you at present and when and if you need to cry, you will. I don't think it is any measure of feeling about the loss of your mum or means that you are not grieving. We all deal with grief differently and there is no right or wrong way. There is no requirement to cry to qualify that you are grieving and numbness is not an unusual reaction to grief either. You will find others on this site who describe feeling that too. Also crying doesn't necessarily make you feel better. Acceptance and learning to live with the loss does, but that takes a long time. There are no rights or wrongs about how to grieve, nor any time frame for it. You just have to find what works for you and work with that from day to day. Things do get better, but it takes a while.
Wishing you well.