If you’re someone that likes to vent and offload I think it’s important to be mindful.
Think about things such as:
How many times have I vented to this person about the same issue?
Has anything changed or am I just repeating the same thing over and over again?
Do I want help solving this or just someone to sit and listen?
The answer to those questions might make you realise that you should spend more time solving your problems than you do talking about them. Your answer might also inspire you to ask before you vent instead of dumping on someone and apologising after.
As much as I think it’s totally fine to want someone to just listen without trying to offer advice, I also think that people have the right no not want to hear you talk about your problems, especially when you’ve gotten into the habit of carelessly dumping on someone over and over again.