Drugs can fuck with your head in and of themselves and make you feel like you need them. Addictions like this are a simple malfunction of the reward system of the brain. That does not make it easy to address. The cravings to use can be uncontrollable. If you really want to stop, don't afraid to seek external help even if it's 'just weed'... I had the most intense psychological addiction to weed out of all the drugs I have ever used including heroin and cocaine. It screwed my brain up too really bad, I had a psychotic break that was directly correlated with my weed abuse. I spent $20,000 in one year on weed, hash, hash oil, bongs etc. so obviously my brain was not functioning properly as that was the top priority. I had no medical purpose whatsoever to use cannabis unless you consider warding off mental and physical withdrawal symptoms a medical purpose which it kind of is in a way I guess since it took me 3 - 6 months before I could lift a finger after I quit.
It started off as a psychological addiction similar to what you describe but it progressed until I couldn't eat food without smoking and the anxiety would cripple me without it. Never had anxiety before weed abuse.
It took 6 - 8 months for the obsessive thoughts about weed and the cravings to go away.
It took 2 - 3 weeks for me to stop puking my guts out whenever I tried to eat food and I was reduced to skin and bones.
The extreme anxiety and chronic panic attacks that were brought on during withdrawal never went away. Actually they got worse. I never had that before I smoked a shit ton of weed, there's an obvious correlation... so maybe that is motivation for some people to quit? That is, if you believe what I'm telling you... that weed screwed my brain with anxiety and panic disorder for life and I know myself better than anyone and I am 100% certain it was caused by the weed abuse in and of itself. I abused weed because I loved getting blazed, simple as that.
I did get my shit together since I quit, and my life is on a better track now but there is more to life than being on the right track... I miss blazing it up and I'm jealous of people who can. I just have mad anxiety issues now so it's out of the question for me. I really miss it sometimes, this seems to happen to a lot of people. Weed starts making them feel like shit, all the positives go away but they still associate it with pleasure and good times so they continue to smoke even though it can turn into a miserable thing.
I know this is not constructive advice, but if you raise your tolerance by smoking more you may find that you get better effects (after a few initial days of feeling shitty). For me weed was always an all or nothing type drug... I was unable in any way, shape, or form to moderate my use of it. If I smoked too infrequently, I would panic and the highs just plain sucked. If I smoked frequently, I would be a typical pothead and it would relax me and make me feel euphoric and chill me out, but then I was get bad withdrawals. Catch 22.