Hi thedru13.
Welcome to our Mattress Forum. 
Thank you for the kind words, and for sharing your story. You are not alone in trying to make sense of all the contradictory mattress information out there. To find the silver cord the best approach is to go to the basics and avoid unsubstantiated advertising claims and reviews. I’ll do my best to help offer some direction.
There is no specific configuration or type of mattress that is good for degenerative disc disease (DDD) because each person is unique and the needs vary with individuals, (as well as varying day to day). I am not an orthopedic spine specialist but generally, a firmer sleeping surface helps with this condition, which you’ve already noticed with your too-soft experience on your current mattress.
It’s possible you’ve already come across this resource on the website with regards to sleeping positions. Side sleepers tend to need comfort layers to be a little softer and/or thicker than back or stomach sleepers. A good starting point for a good comfort layer for a side sleeper is 3" and then depending on weight, body shape, preferences, and the firmness of the support layers, to go up or down from there. Most side sleepers will fall in the range of from 2" - 4". Because you have your back to consider, less layer thickness with a higher foam or layer density is going to likely be your best bet.
As for sleeping hot… I am not sure if you have come across some of our many topics that discuss temperature regulations issues, but you can read more about the many variables that can affect the sleeping temperature of a mattress or sleeping system in post #2 here more about tracking mattress temperature regulation issues potential causes ~ Post #2 here and the posts it links to that may be helpful. You may also be interested in the information in post #28 about temperature regulation and mattress microclimate.
As a rule, latex sleeps cooler than all other foams.
Right off the bat, I would say the DreamCloud Premier may not be your best bet option. It is primarily a memory foam mattress, and memory foam notoriously sleeps hotter than all other comfort layer foams regardless of any gels or temperature mitigating additives the foam contains. They also do not list the density of the foams they use, so it’s hard to know if the comfort layers will meet the mattress durability guidelines here to ensure that you will sleep at the desired level of comfort/support for a long time before you need to replace the mattress. Especially with your DDD condition, you cannot afford to allow for the possibility of any weak links in your mattress. As a rule, when it comes to memory/polyfoams, you want to make sure that the density of any polyfoam is at least 1.8 lb per cubic foot or higher, and that memory foam (or gel memory foam), for a one-sided mattress, is at least 4 lb per cubic foot.
Because DreamCloud doesn’t openly provide their mattress specifications, that would be a red flag but, if you can find that information, I’d be happy to evaluate it for you.
The Helix Luxe comes in several different models. Which were you considering?
The Nectar is a mattress that comes up a lot in the forum, so we happen to have their specifications handy:
[indent]1" (14 ILD) Quilted Cover (Tencel/polyester cotton)
1" of 4lbs (15 ILD) semi-open Lush Foam™
3" of 3 - 3.5 lbs. (45 ILD) Transition Layer
6" of 2.2 (45 ILD) HD Polyfoam[/indent]
The concern with this mattress is the 3" inches of 3 - 3.5 lbs transition foam is still subject to high mechanical stress and compression forces. It may not lose its supportive qualities relatively quickly leaving you looking for another mattress in only a few years and accentuating your DDD condition…
Stay away from reviews!! People often review mattresses far too early after receiving them, and reviews lack specific information about all the variables that can contribute to the suitability of a mattress (like details about the person and the mattress) that would make them more meaningful/accurate. I’d suggest reading about the dangers of making a purchase based on reviews here. The same goes for review sites that more like revenue sites.
I agree with your assessment thus far on going towards a hybrid …personally would recommend taking a look at the hybrid options our Trusted Members offer. Not only are they going to provide you with a durable mattress, but they are also open and transparent about their materials, foam or layer densities, and more than happy to speak with you about your preferences and needs to get you the best fit possible.
Based on the options you mentioned above, I’d suggest having a look at…
The Select Sleep Hybrid by Sleep EZ
The Ultimate Hybrid by Arizona Premium Mattress
The GhostBed Flex and GhostBed Luxe by GhostBed
Luma Sleep with its hybrid Luma Mattress
The Natural Escape by My Green Mattress and the mattresses offered by their sister company, Quality Sleep Shop.
The Alexander Signature Hybrid and Natural Hybrid Latex by Nest Bedding
There’re likely others that I failed to list, so do take a moment to browse our other Trusted Members.
While I always steer subscribers away from mindlessly purchasing a mattress just because it can be returned, I advise thorough research (just a you do) but I do recognize that there are legitimate situations where things can go wrong and a good mattress return policy is important. All of the above have in home sleep trials, and varying return-exchange policies so you’re not ultimately stuck with something it may not work for you. That said, I’ll reiterate that if you speak with any of them directly, they’ll work with you closely to provide you with the option that is most likely to be suited to you.
I hope I haven’t overwhelmed you! Please do let me know if you have any additional questions.
Phoenix
