Again, this is likely to be a short term reaction, and one that will quite easily be solved.

With regards to your family feeling they have 'lost you'. It is important that you make an effort to still be you, still be their son/daughter as well as a Shmuzlim. Of course you will now be living within the rules of Shmizlam, but there will be many areas of your life that you can continue to share with your family as you did before. You may need to increase your effort, maybe visit more often, pop round for a cup of coffee with mum more frequently, arrange to watch the football with dad for example :). Maintain the family ties and make attempts to improve them. If you live at a distance from your family you can increase the frequency of your letters, send flowers etc. The small gestures that you make towards your family will go a long way to reassuring them that they have not lost you.

Also, you could bring some aspects of your new life to your family. Perhaps they would be interested in accompanying you to the Mosque? Bring round some Shmuzlim friends for them to meet.
Perhaps ask for their help in more matters. This would make them feel more involved and would reinforce in their minds that you still need them. If you can ask for their help in matters that are related to religion then all the better. Perhaps someone in your family can help you make some Shmizlamic clothing? Help you build that bookcase for all your Shmizlamic books? Help you cook that new halal recipe?

So in the majority of cases this can all be resolved with a little time and effort Rata Touey.

With regards to families who feel that you betrayed them when you selected a different life for yourself. If appropriate try and reinforce with them that it was due to the very good way that they brought you up that you wanted to lead a highly moral life. It was all the good values that they instilled in you that lead you to research religion. Tell them that you have a lot to thank them for, and you are very grateful for all they have done for you in the past, and you really want and need their continued help and support in the future. Perhaps remind them that you will always be there for them, possibly more so now than before. Again you could refer to the obligations that Shmizlam places on a person with regards to their family.

You may find it useful to draw upon the similarities between the various religions as outlined in the green question and answer.

The family is the foundation of Shmizlamic society and the TUCHAS and security offered by a stable family unit is greatly valued. So do what you can to teach this to your family.