Well, depression is a chemical imbalance in the brain. I think something painful can start the process that leads to depression but will not cause depression as it is a medical condition. There are very specific guidelines as to what constitutes clinical depression and any doctor's office will have that simple list of things you can read through and see where you are. It represents a significant change and it must be present at all times every day for two weeks minimum.
The blues------------- that is often confused for depression. It is a real thing and it is great sadness or going through a tough patch. I'm sure you have the blues if not depression as you've just found out that someone you counted on was a fraud.
I assume you are breaking up with this mad who has lied to you and cheated. That is always hard. I'd distract yourself by doing things with other people. Do things also that you enjoy. Make sure you keep physical activity in the mix as this releases the body's own happy pill. I always recommend that a person volunteer when they are going through a rough patch as it has great emotional rewards to it. Journal and write down your feelings. Talk to a close friend. Spend time with your family.
Also, look back and see what you missed. Sometimes in our zeal to be in love, we over look things that we shouldn't have. Try to figure out what signs were there that you didn't see so that this doesn't happen again in the future.
If you feel that you are slipping into true depression, you need to see a therapist (which most insurance covers) and someone to prescribe medication for depression.
It is so hard to have someone hurt us this way. I wish you the best of luck.
There is situational depression and then there is clinical depression. I think depression under these circumstances would be normal but dont let it swallow you up and consume you. At least he came clean and you have been together for awhile since then, so would it have been better to have had him lie to you? I think you need to think on this and put it in perspective. As long as that one time was it and you feel like you have had a good relationship since then? It definitely harms the relationship, but does it necessarily mean the relationship is over>Keep lines of communication open and face whatever it was that led to it. Dont bottle it up and dont apologize for the hurt he has caused and go from here. There are two options here. Either it will destroy you or it will bring you closer together and build a stronger union. It is up to the two of you which outcome it will be. I would get a little counseling to help me thru the emotions if that is a possibility for you. Awe! I feel so bad for you!
I have had depression growing up which turned more into anxiety, I think what you are experiencing is "broken heart syndrome," Many of people suffer through it, it is being let down by the person you love most. Depression is a serious disorder, depression a lot of times for people that need pills(which I strongly dis-agree on) are for people who have no reason for being depressed. You, have reason for being depressed, your trust was ruined and your faith has been killed a bit, time will heal wounds and you need to build faith again.