Be prepared that you might have some negative response from your family. Very important
1. Be extra nice, respectful and polite to your family. Show them you are a better person now. Hug your mother, show them that you are still close to them.
2. Chose the right time to tell them and when you tell them that you are a Muslim, reassure them that you are still their son, still very much part of the family and nothing change.
3. Ask them what are their concerns and clarify any misconceptions. Engage in long conversations as long as they are will to listen and explain everything they want to know about Islam.
4. Do not expect them to accept your practices immediately. Give them time. For example, if they do not want you to pray in the house then don't do it in the house.
5. Do not hurt your mother but not eating what she cooks, just tell her you have to refrain from eating pork and meat has to be halal. Go buy halal meat for her to cook for you so that all of you can eat together. Be sensitive to their feelings.
6. Tell them life goes on the same except that you have to be a better person to be a good Muslim. Try explain to them all the good things that you are doing now which you never did before. Convince them that Islam teach you to be a better human being,
7. Lastly if they are angry and say things to you which make you angry, never retaliate with rude words or raise your voice. Just smile and patiently explain to them.
Only you know your family better so maybe you can expect what their reaction is going to be so you have to prepare your response to them. I don't know them so I am giving you general guidelines only. Wake up in the early morning before your morning Farj prayer and perform 2 rakaat of Tahjud prayer and ask Allah to make it easy for you and guide you how best to tell them.Make a lot of doa after every daily prayers. Insha Alllah you will be alright..