hi Sav... welcome to CC. Just a quick heads up, i'd be careful with your language. If the moderators see you with repeated offense they could decide to ban you, since there are rules about it. Just a friendly tip.
Also, if you are a Christian you may want to rethink your use of the term 'karma'. Merriam-Webster puts it this way...
kar·ma/ˈkärmə/Noun
1. (in Hinduism and Buddhism) The sum of a person's actions in this and previous states of existence, viewed as deciding their fate in future existences.
The 'previous' and 'future' states of existence refer to reincarnation. The belief that a persons soul returns to earth over and over again, in different forms, being birthed and dying. the idea being that each 'existence' we hopefully grow until we 'ascend' beyond needing to grow more. I maybe be a bit off on the exact details, but as a blanket explanation its right.
Really karma is you build up good or bad within 'the universe', (basically 'god') and which you build more up of the universe gives it back in return. The nature of the word goes beyond just the simple idea of consequences and takes our actions and puts them into the hands of 'god' (the universe, where we are all one with god, and are all god) and this force acts on us. Not quite the most scriptural concept.
Again, i may be slightly off on the details, but the general concept i'm giving is right, i know. i know it sounds similar to the 'reap what he sows' in the bible, but its totally different at its heart. Once again, a friendly tip, no offense intended.
To your question about 'repressing thoughts'.. actually, it depends on the thought. If you're having thoughts of doing wrong things, then yes, you should push those out and not dwell on them. Or any negative thoughts. Now something like, wishing to go back to a previous positive time in your life... well, its a natural thing to do. And if you've just recently had a break up, its definately natural. But i also think its a bit detrimental. All you're doing is allowing your thoughts to dwell on the past, and chances are you will romanticize and idealize the relationship to be better than it really was, causing you to miss it/her more.. which only leads to a bad cycle of thinking. So don't beat yourself up over when it happens, but i would encourage you to work at avoiding those thoughts. in the long run its the better way to go.
Just remember there's a difference between pushing your thoughts down, stuffing them.. and not letting them run you. you can think about your ex, your previous relationship, but the concept is be in control of yourself and your thoughts so that you don't end up like i mentioned in my last paragraph. so the idea isn't to not think about it, its about not dwelling too much, or letting those thoughts control you.
Hope some of this helped. take care.
. God is in control of all and we must focus on Him, not something not of God such as Karma. I pray that you stay strong in this situation! If you ever need anyone to talk to, we are here in the forum and in chat.