I think the simple answer to your question is No, you are not crazy or even close to it. Any shock or trauma to what we consider our normal state of mind can sometimes make our subconscious mind work in strange ways.
The loss of your husband is such a case, whether his death was sudden, or expected, the result of an illness perhaps, you do not say but either case will react with the subconscious mind. You mention you have children and I suspect you may be putting on a brave face for their benefit and of course the two who seem similarly effected maybe doing the same in return.
Personally I do not believe in ghosts but I do believe in the overwhelming power of the human mind and our mental ability for self preservation. It is possible, albeit subconsciously, that both you and your children derive comfort in the belief that your husband, their father, is still around and perhaps spiritually still there to protect you. If this is the case where is the harm ?
This is not craziness, these a merely our mental tools that are triggered to help us cope with the problems life throws at us.
The feeling will pass as you learn to adjust to the pattern of your new life, or not as the case maybe. You may be happy for the feelings, if they are indeed a comfort, to continue for as long as you need them although I’m not sure that would allow you to move on as you should.
I am sorry for your loss and I do hope this helps you.