She is still not sure if I am the one!

I have been dating a girl who wants to get married to me but is also unsure about our relationship because she has been with too many guys before and none of them have worked out. We have been together for a year and things are going great, but there is a part of her that is constantly afraid that things will fail. I have tried my best to reassure her and keep telling her to focus on the present and future, not the past, but she can’t seem to shake off her bad experiences. I am willing to make a commitment but can’t until she starts to feel stable with me. How do we fix this situation, so we are both in a better frame of mind and better prepared to work together towards a future together?
You can start by acknowledging that she hasn’t addressed some aspects of her past, and that she may not have the tools to be able to do so. Your actions make a huge difference, so continuing to be supportive while she works things out is the best approach. Time will make her feel more comfortable with this relationship, but it may also help if you can both consider speaking to a professional about why your individual needs are not being met at the moment. First try and decide if you really want to be together, then commit to working on this even if it means turning to a therapist for help because there is no shame in asking for it.

My boyfriend has a nasty habit of cracking awful and hurtful jokes because he thinks they’re funny. He ends up hurting a lot of feelings but doesn’t seem to understand that people are slowly beginning to tire of him. How do I get him to stop doing this?
There may come a time when he looks up and finds that everyone he was once close to has gone away. Until then, all you can do is call out his behaviour.