<human>: Summarize the given text in a few sentences.

Having a lot of issues with my girlfriend and she left to stay the night at her mom's a few weeks ago because of how bad everything got. She's back now and we're trying to slowly work things out without overwhelmingly each other again and I keep going into panic mode and fucking everything up by being clingy. 

I've always had trust issues (even though she never really gave me reasons too, I'd just find inconsistencies so often I started feeling like she wasn't trying to keep my trust but I realize now I sort of pushed her into doing that) and its like they're even worse now because I'm afraid of her leaving. So now when I try to be affectionate and get shut down (or in some cases, just treated how I used to treat her without realizing) it brings me crashing down into depression and anxiety wondering if she still wants to even be around me which leads to trying to be more affectionate (cause that makes sense?) and I end up being the overly clingy boyfriend who always needs more attention. 

Doing all of this is making our whole situation worse and probably making her sick(er?) of me but it's so hard to not feel that way even knowing all that. It's like I can't stop myself from acting that way and it's because I can't stop feeling that way. 

How do I calm down and stop worrying about our relationship, so that I can have a chance at actually fixing it?

I've had anxiety like this before when I quit smoking (weed, withdrawal is noticeably worse for me than others) and she's always been there to help me deal with it (too much so, which is part of the problem) so this is even scarier and harder since I no longer have her for that. And I'm cutting back on smoking now as well just to clear my head but I know it's also contributing to the anxiety. This is probably just irrelevant information though. But I know some ways to deal with anxiety already this just seems too intense to even start any of them.
<bot>: How do I calm down and stop worrying about our relationship, so that I can have a chance at actually fixing it?