I broke up with my ex of 3 and a bit yrs September last year. I am not a particularly happy/bubbly person and I guess she got sick of being with me. She said shed stopped having fun.

We work in the same industry and so see each other occasionally. But we don't talk any more or anything. She hasn't tried to get in contact with me since we split so it definitely seems to be over.

The only problem is, I miss her heaps. Whenever I'm not doing something or even when I am its hard to not think of her.

What should I be doing?

Having fun.

Doing positive things for yourself and enjoying people that do care, ones that don't get sick of you.

After 6 mo. You are already living your life w/o her.

Missing her doesn't serve you in any way.

Do whatever you want. Live life.

Check out the list of things to do after a break up: https://www.askmehelpdesk.com/relationships/list-things-do-after-breakup-78597.html

I would be enjoying my life, and have a bunch of options, and opportunities, lined up for this week end.

If I had the strength after Friday Night!! (Bowling, Karaoke, and Dart )

I have been trying to keep busy hanging out with old friends and trying to make some new ones, furthering myself and what not...

But it just seems like I am just filling in time. Nothing really seems to matter that much

Good that you are doing that. Keep it up.

We go through that during breakups.

It takes time. Be patient. Do the right things for yourself.

That means ridding your conscious mind of unnecessary things. And focusing on things that make you happy.

I would hope you still have those moments. The ones that you don't even thing about at the time cause they are so nice.

Those are the ones to focus on, to have those most of the time. And recognize them. You already know the bad feelings.

Don't ever feel like you are wasting time. This is your life. Minute by minute.
A learning process dictated by you.

You sound low,maybe you should talk to your doctor?

I'm suggesting this since you wrote'nothing seems to matter much'.