I have a lot of issues and insecurites with my man someone please help me to get past my feeling fear of being cheated on again and being walked all over. How can I get him to understand without coming off as to naggy and making him fall out of love with me

You must first deal with your own issues. But what ever your issues may be, NEVER LET A MAN WALK ALL OVER YOU.

You must respect yourself before anyone else respects you. You must demand respect at all times and you deserve it.

You should first better yourself. Whatever it takes to better yourself. Learn new skills, learn to cook, buy new clothes, WORKOUT, buy lingerie for him, be sexy for him, learn to satisfy your man, whatever you desire.

When you better yourself, you will stand taller. You will have more confidence. You will feel that you are more woman that any other woman can be to her man and you will have confidence that HES ALL YOURS and you can SATISFY all his wants.

But note that do all these things for your man ONLY IF your man is acting like a MAN, not a little boy. If he is treating you the way you deserve to be treated as a woman.

Be a real woman and hell treat you like one. He has no choice.

You can start by reading some self-help books:
The Guide to Self-Help Books – Recommended Self-Help Books - Self-Help Book Reviews

Secondly, you shouldn't start a new relationship if you haven't spent enough time working on yourself and your past insecurities. That's unfair to your new boyfriend. Since you already started, then I suggest that you slow down the relationship. This is an internal battle, so you need to spend more time working on yourself.