Hi lostandlonely welcome too the forum.It is easy to feel disconnected when you lose those around you as they are your connection too society and lonliness can drive us to being increasingly depressed and then anything at all feels like an even bigger effort.
Perhaps there is a way you can reach out too others through volunteering or joining something -maybe an evening class,or something your local community has going on, By participating in something like that you may meet new people and with a common goal, whereby you are helping a cause, or learning something new, friendships will develop from that thing you have in common.
If going out is an issue for you, I have found doing online courses not only fills my time, but by learning through several different courses has given me new direction. futurelearn do free courses on many different topics, theyre short and dont require a lot of commitment, but they may inspire you to go on and study further,you also communicate - again online with others on the course so that you are interacting with other students.I know its not the same as real world but if shyness is holding you back, then it can give you more confidence to overcome that.
What brings us here is bereavement and the grief that loss of our loved ones brings us and lonliness, as you will have seen reading through,is a big part of that - but we also find we have other things in common - thats why we have an everyday chat section because sometimes as well as support for the big issues, having some-one to chat too about those things is another part of what we miss which adds to the loneliness.
Also it helps to write about the loved one we lost, because in doing so we start to remember them in life and focus on that rather than their loss - so feel free to start your own topic in introduce yourself section and tell us about your mum, and join in the everyday chat too.