I experience driving anxiety in very specific situations and I’d like to learn how to ease it, at least to some extent. I feel like I almost don’t trust my own judgment while driving (despite the fact that I feel I always drive fairly well and cautiously), and I fear unexpected movements from other drivers as well. 
Situations that cause my driving anxiety are: 
-Left turns where there isn’t a guaranteed green arrow (ESPECIALLY on multi-lane stress with lots of businesses). Residential/quieter roads are slightly less stressful when it comes to left turns for me. 
-I even stress out at right turns when it’s a fast and/or busy/multi lane road I’m trying to turn on to. I needlessly wait and wait to turn because I never trust the correct time to go, even when there’s plenty of space between me and an oncoming vehicle. This applies to left hand turns too. 
-Driving on the freeway unless it’s fairly empty. Merging is especially nerve-wracking. 
-I love the mountains and the outdoors, yet driving into a canyon or area without service alone gives me crazy anxiety. Yet I feel totally at ease when with someone else. I would like to be able to take scenic drives in the mountains alone without having this fear. 
-I have an amazing Subaru with great snow tires that can handle snow, yet I get extremely panicky when I cannot see the lines on the road due to snow, rain, or even sun glare. 

The only situations in driving that don’t give me anxiety are quiet, residential roads, or single lane, middle-nowhere type roads. 

Any tips as to lessen general driving anxiety would be very much appreciated!