Go for it! The hee bee gee bees will be gone once you are on the road. I don't think much about the gear anymore, but I usually get worked up about some minor perceived injury before the trip. Once I am rolling I don't even think about it anymore. Part of the joy of bicycle touring is realizing that all that $hit doesn't matter. I think you will be fine based on your experience, but since you asked
My records for JULY cycle touring in the USA are 26 degrees F near Chemult, OR, and 115 degrees F at Hite, UT. I stop short of fleece, but I would recommend light weight long underwear (top+bottom). I also bring a heavier weight shirt. On the coast I find I ride in my leg warmers and long sleeve riding jersey a lot. The long sleeve riding jersey and the heavier weight shirt are a bit redundant, but whatever I ride in stinks and I like to have an alternative for passive activities. In the mountains I like to be prepared for 30 degree F summer mornings. Although not as extreme, it also can be surprisingly cold on the coast in the fog.
Here is a list I work from when packing. I don't necessarily take every item on every trip.
1 T shirt
1 Nylon long pants
1 Wallet (money, credit cards, id)
1 short sleeve riding jersey
1 long sleeve riding jersey
2 Riding shorts
1 Nylon shorts (camp, swim)
1 Leg warmers
1 Light polypro top (or lightweight smartwool)
2 Bike socks
1 Polypro balaclava (or smartwool)
1 Polypro gloves
1 Sun hat
1 Thick polypro shirt
1 Polypro long underwear bottom (or lightweight smartwool)
1 Small Towel
1 Flip flops or crocs
1 Bike shoes
1 rain coat
1 rain pants
1 Helmet
1 Bike gloves
1 Headband
Passport (international travel)
Passport wallet (international travel)
1 Waterproof socks (very nice in wet places like Russia, I would not bring these in the USA)
Glasses
Mosquito repellent
Sun screen 50
Sun screen 15
Aloe vera gel (for sunburn or chapped skin)
Chap stick w sunscreen
Aspirin (anti inflammatory)
TP
Kleenex
Hand wipes
Sewing kit
Tooth brush, paste
Shampoo
Body Soap
Visine
Antacid
Neosporin
Gauze pads
Adhesive tape
Prepackaged sterile scrub brush
Sleeping bag and stuff sack
Tent w/o ground cloth, w/ poles, stakes, fly, stuff sack
Blue foam pad
Straps to tie tent, sleeping bag pad to rack
Rear bike light
Front bike light
Patch kit and tire levers
Spare tube
Chain lube
Spare spokes w nipples
3 Bike bottles
Ink pen, also good for marking holes in tubes
Bike tools (allen wrenches, open end wrenches, small screw driver, short combo headset/pedal wrench, spoke wrench, adjustable wrench, chain tool)
Spare bolts, nuts, master link, kevlar spokes
Lock tite
Bike lock and key on loop to put around neck
String
Pump
Maps
Camera
Swiss army Knife (corkscrew, bottle opener, can opener, blade)
Pot w lid
Cup
Spoon
Fork
Water purifier w/ fresh chlorine drops
Rope to hang food or use as clothes line
Garbage bags to keep stuff dry
Zip lock bags
Stove w/ lighters
Pot pliers
≤4 1L Collapsible water bottles (depends on climate, camping facilities)
Camelback (desert only)
Power bars or other anti-bonk food
Dish soap
Dish scrubby