How to deal with a jealous colleague
I ‘m worried about my colleague who is always on my case about me being the younger person but being assigned huge responsibilities.
This affects me somehow because he’s always jealous about me being part of projects he is excluded from. Some other people his age have occupied better positions than him.

It does need to be addressed though, because if ignored, it can lead to an unpleasant atmosphere. There is always a danger that he will try to sabotage your work, or discredit you.
So first try to befriend him, make an ally of him. And if that doesn’t work, you need to tackle it another way, perhaps by involving your management.
We have dealt with this topic in detail on the site, and it may be useful for you to revisit these lessons
Minimising Conflict In The Workplace
Tools and Techniques for Handling Conflict in the Workplace
Tackling Conflict In The Workplace
You need to build bridges with him. Don’t show off about your achievements, and praise his performance whenever you can. Give him credit for his positive qualities, and praise his achievements. Without drawing attention, quietly acknowledge his strengths and his accomplishments , celebrate his success.
Perhaps you can mentor him, help him to be more successful.
Don’t display negative behaviors toward him, he will feel justified in retaliating. Try to be happy for him, and refrain from measuring his success against yours.
But if you can’t achieve this, be aware of the dangers, and take steps to protect yourself.
Be careful not to “add fuel to the fire.” If he spreads rumours about you, don’t respond in kind. Ignore him, and maintain a professional and pleasant attitude at all times. If he does attempt to discredit you, or sabotage your work, or acts in a confrontational manner, this will affect your productivity, as well as your reputation.
In this case, you will need to keep a journal of any incidents, noting the date, time and brief details, as well as witnesses who could support you. Keep any offensive notes, or emails.
Once you have a reasonable amount of evidence, consider reporting the issue to your manager or your human resource department.
I hope this has helped you to tackle a very difficult situation