The office introvert?

Hi everyone,
I went back to office work a year ago after 16 years of being a mother, and then a 'nurse' to my husband who took very early retirement due to health issues. I am a quiet shy person but do make the effort to try and talk to people, and I think I am on good terms with most people in the office.
I think my concern is I am not good at banter and small talk, I find it very difficult to start a conversation, and feeI I don't contribute much at the best of times. I think people think I'm boring.
We can't afford for me not to work; how do I get over feeling isolated at work, how do I form better work relationships? The job in itself is ok, but I don't look forward to breaks etc where there is socialising to be done! I do have these feelings of self-doubt, self-worth and wonder if people even want me to sit with them. I wonder if I am introverted?
I would love to hear from anyone who has had similar experiences. Thank you.

I've always had an issue with socializing. I'm ok one on one for quick conversations, but the longer the conversation gets and the more people you add to the group the worse it gets for me. This is true with work and extended family.

I have learned, for myself, that I'm ok with that. My family is used to it, and my co-workers are used to it.

That doesn't mean you should strive for that. There are ways to improve communication skills for introverts. I just don't have the energy to try. One of the issues that I have is that in large groups, when there is more than one conversation going on, I can't follow any of the conversations because they all interfere with each other.

So -- no real help here, but I do understand.

Yes I understand too, and I think it's okay to be who you are, some of us are just quieter.

It is OK to be quiet in a group. If you are uncomfortable, then people just reflect that back. If you are comfortable, then people will be comfortable too.

I had a work group where there was a quiet guy. It was fine! We liked him.

Listen for things to follow up on later. Ask people if the car is ok now if it broke down. Then they know you care.

Thank you all for your replies. I can relate to too many conversations going on, completely overwhelming; my hearing isn't 100% either which doesn't help! Yes, I understand what you mean by vibes, people can pick up on when things aren't right.