Too much of anything will decrease the mental and physical perception and sensitivity.
Example: eat an entire box of cookies, the last one does not taste as good as the first one. The last one is almost just a requirement/work to finish it.

I wouldn't think so. Just keep a delicate touch to heighten the sensitivity.

It won't decrease the sensitivity, but you may find yourself getting bored with the same routine, making it take longer and going to more effort to reach climax.

That was the problem I had in the past. Doing the same thing over and over was great at first, but after a while it took longer to cum, or things that would make me cum (certain porn, stories, etc.) Didn't do the trick anymore.

Oh wow yes that is kind of what has started to happen and what has made me worried. I have stopped all together now. Im affraid it will damage my relationship and intimacy between my partner and I.

I totally get you. Especially with my anxiety issues, for some weird reason my main coping mechanism has always been masturbating, because that release makes me at least feel better in the moment.

The problem became when I was masturbating a ton back when my panic attacks were really, really bad... I had that problem I described, where after a while the same old routine just wouldn't cut it anymore.

Personally, what worked for me was something as simple as changing things up a little bit. Even something simple (doing it in a different room, watching a different type of porn, etc.) was enough to do the trick.

I think those are good tips. My only worry I guess is running out of ways to switch it up and getting bored with everything. Im going to see how long I can go. It gets easier with time so far. I do think about it daily though. I have been doing it from a very young age. I think unfortunatley because of some sexual trauma I went through.

I'm very sorry to hear that. Good luck in anything you try to make yourself heal and feel better! We are all here to help and support each other.