There are many things that can be very toxic and deadly to a relationship. One of the worst is unfounded or over the top jealousy. If you find yourself in a relationship where jealousy is a real problem do yourself a favor and learn how to deal with jealousy in a relationship as soon as possible before too much damage is done.
The first thing you need to do to learn how to deal with jealousy in a relationship, is to identify where the jealousy is coming from; is it your jealousy, your partner's jealousy, or worse yet, both of you who are suffering from the green eyed monster?
Out of all of these possible scenarios the one that will be the "easiest" to deal with will be the one where only you are the jealous one. Why? Because, you can't change someone else. They have to want to change and if it is your partner who gets jealous for no reason, you can't force them to make changes.
But, if it is you who gets ridiculous every time your partner glances at someone else, you can make changes to yourself. It won't be easy and it will take time, but if you want to do it badly enough, you will find a way.
You need to try to identify why you are so jealous. Most of the time the reasons for excessive jealousy are insecurity and/ or you've been cheated on before. Trying to overcome these past betrayals will take a lot and it may be a good idea to enlist the help of a professional. A counselor may help you gain a better understanding of who you are and why you act the way you do.
It's important to remember that learning to change is a process. It's not about right and wrong as much as it's about cause and effect. It's not really "wrong" that you get so jealous but it is causing problems for you in your life and relationships.
Since it isn't serving you, it's time you found a way to get past it.
If it's your partner who is the jealous one they no doubt have become overly jealous due to the same circumstances; they are insecure and / or someone cheated on them in the past.
The problem is that you can't force them to take the steps and put in the work to change. Unless your partner recognizes how toxic their behavior is and is willing to do what it takes to make things better, your relationship will always be a roller coaster ride that you will probably get tired of eventually.
Unless your jealous partner commits right now to getting some help and dealing with these issues, you really should consider ending the relationship and moving on. Jealous behavior almost always escalates with time. What started out as just an annoyance can easily turn dangerous and violent over time.
You really don't want to hang around for that.
Learning how to deal with jealousy in a relationship is challenging but it can be done. It really just depends on the maturity level of both of you. If both of you are mature and committed to making things work than you have a chance. Good luck.