Never apologize for needing to vent. Your feelings are your own, you can't stifle them. If other people are offering to listen to you, you shouldn't feel bad: you should honestly trust their ability to tell you when they don't want to do something. It doesn't sound fair if someone says "vent to me" and then says "I'm annoyed with you for venting." That's completely unreasonable.
Thank you :'). It's just that I've heard so many people tell me I'm annoying for venting so much and it's gotten to the point where I hide how I truly feel :').
Well that's a little rude. Never apologize for your emotions. Apologizing for having emotions is like taking the blame for a tsunami. It's pointless and will only weigh you down.