I'm sorry you're going through this, I recommend that you express everything by typing it all out and venting. After that you can try to better yourself step by step. because in the end all u have is yourself. :)
First I'm feeling like I'm either to much on someone coz when I'm in something I give it my all I just broke up with my best friend and I'm feeling also kinda of overwhelmed with my relationship
never blame yourself. you are never too much, it's either the person accepts the love you give them, or they don't and that can be their loss. I'm sure you deserve the love tht you show to everyone else. so I say cut the person off, because if they make you feel like you trying too hard then they aren't worth it.
a relationship shouldn't make you feel overwhelmed. try speaking to your partner and communicate everything you need answers to. that's the only way to find out if you are settling for less or not.