Everything takes time and practice.  When I was in my twenties, i had an alienating job talking to others on the phone and working in a cubicle.  My social skills suffered.  I became very lonely and felt very isolated because i lived in a large city without family.  After many years of this type of work, and increasing loneliness,  I took a job where I was forced to small-talk and socialize all day.  At first this was very difficult and awkward for me, and I was full of anxiety.  After awhile, I became more and more comfortable talking to others and not feeling self-conscious.

Keep working at being in social situations.  Join a volunteer group or faith community.  Join a group where you have common interests with others.  Don’t give up on yourself.  So much of happiness and social skills are derived by a sense of self-confidence.  If you like you, others will like you too.  Easier said than done of course, but ask yourself how you can gain the confidence you need.  Loneliness is a difficult thing, and it can become worse if you feel shame about it, but remember that it is just a temporary feeling, and with lots of practice, and the right life-affirming environments, you will realize that loneliness can be overcome.  I also recommend reading any Pema Chodron books.  She makes you realize that none of us are truly alone, we are all connected if we are just able to see it.  Best of luck, and sending love.