I am sooooooo tired

Yes, a blood test is a good idea.
You're right to be cautious about driving when tired. I think that's why I had my accident last year. I was meant to drive my friend into the town today, but felt tired after a sleepless night so didn't go. Slept all morning.
As others have said, you've had all the responsibility for some time now.

I think you need to get checked out by your doctor to be on the safe side but I think maybe also you are having to do too much and need a jolly good rest. Easier said than done I know. My husband falls asleep as soon as he sits down and has even been known to close his eyes when we've been out for an evening (maybe he's trying to tell me something). He had various blood tests which were all fine. He's 65 this year and overweight and still commutes to London every day so I understand why he's permanently tired.

It's the ongoing strain of being the one who has to do it all, probably. You're worn out. The one moment I lost concentration at the wheel was a while ago when I was ferrying husband back and forth from hospital, managing all the day to day house stuff, trying to do things with other members of the family......Just trying to do my best like you are. But yes go and talk to the doctor. Though maybe you just need a good rest

Agree with hulahoop. Extreme tiredness and putting on weight with no explanation are classic symptoms of T2 diabetes.

Sorry you are feeling so tired go to dr and get some blood tests as others have suggested are you diabetic ? Hope you feel better soon .

Get a thyroid blood check, I have problems with mine and if my Thyroxin dosage is not right I will feel desperately tired. Regular blood tests and right dosage and I feel fine. Might be worth considering.

Get tested for iron deficiency.